MIPS: convert IO port accessor functions to 'static inline'

The currently used 'extern inline' directive causes
the following compiler warnings if CONFIG_SWAP_IO_SPACE
is defined:

  <...>/include/asm/io.h:345:1: warning: '__fswab32' is static but used in inline function '__outlc_p' which is not static [enabled by default]
  <...>/include/asm/io.h:345:1: warning: '__fswab32' is static but used in inline function '__outl_p' which is not static [enabled by default]
  <...>/include/asm/io.h:345:1: warning: '__fswab32' is static but used in inline function '__outlc' which is not static [enabled by default]
  <...>/include/asm/io.h:345:1: warning: '__fswab32' is static but used in inline function '__outl' which is not static [enabled by default]
  <...>/include/asm/io.h:344:1: warning: '__fswab16' is static but used in inline function '__outwc_p' which is not static [enabled by default]
  <...>/include/asm/io.h:344:1: warning: '__fswab16' is static but used in inline function '__outw_p' which is not static [enabled by default]
  <...>/include/asm/io.h:344:1: warning: '__fswab16' is static but used in inline function '__outwc' which is not static [enabled by default]
  <...>/include/asm/io.h:344:1: warning: '__fswab16' is static but used in inline function '__outw' which is not static [enabled by default]
  <...>/include/asm/io.h:341:1: warning: '__fswab32' is static but used in inline function '__inlc_p' which is not static [enabled by default]
  <...>/include/asm/io.h:341:1: warning: '__fswab32' is static but used in inline function '__inl_p' which is not static [enabled by default]
  <...>/include/asm/io.h:341:1: warning: '__fswab32' is static but used in inline function '__inlc' which is not static [enabled by default]
  <...>/include/asm/io.h:341:1: warning: '__fswab32' is static but used in inline function '__inl' which is not static [enabled by default]
  <...>/include/asm/io.h:340:1: warning: '__fswab16' is static but used in inline function '__inwc_p' which is not static [enabled by default]
  <...>/include/asm/io.h:340:1: warning: '__fswab16' is static but used in inline function '__inw_p' which is not static [enabled by default]
  <...>/include/asm/io.h:340:1: warning: '__fswab16' is static but used in inline function '__inwc' which is not static [enabled by default]
  <...>/include/asm/io.h:340:1: warning: '__fswab16' is static but used in inline function '__inw' which is not static [enabled by default]

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Cc: Daniel Schwierzeck <daniel.schwierzeck@googlemail.com>

arch/mips/include/asm/io.h

@@ -254,7 +254,7 @@ out:
  */
 
 #define __OUT1(s) \
-extern inline void __out##s(unsigned int value, unsigned int port) {
+static inline void __out##s(unsigned int value, unsigned int port) {
 
 #define __OUT2(m) \
 __asm__ __volatile__ ("s" #m "\t%0,%1(%2)"
@@ -268,7 +268,7 @@ __OUT1(s##c_p) __OUT2(m) : : "r" (__ioswab##w(value)), "ir" (port), "r" (mips_io
 	SLOW_DOWN_IO; }
 
 #define __IN1(t,s) \
-extern inline t __in##s(unsigned int port) { t _v;
+static inline t __in##s(unsigned int port) { t _v;
 
 /*
  * Required nops will be inserted by the assembler
@@ -283,7 +283,7 @@ __IN1(t,s##_p) __IN2(m) : "=r" (_v) : "i" (0), "r" (mips_io_port_base+port)); SL
 __IN1(t,s##c_p) __IN2(m) : "=r" (_v) : "ir" (port), "r" (mips_io_port_base)); SLOW_DOWN_IO; return __ioswab##w(_v); }
 
 #define __INS1(s) \
-extern inline void __ins##s(unsigned int port, void * addr, unsigned long count) {
+static inline void __ins##s(unsigned int port, void * addr, unsigned long count) {
 
 #define __INS2(m) \
 if (count) \
@@ -311,7 +311,7 @@ __INS1(s##c) __INS2(m) \
 	: "$1");}
 
 #define __OUTS1(s) \
-extern inline void __outs##s(unsigned int port, const void * addr, unsigned long count) {
+static inline void __outs##s(unsigned int port, const void * addr, unsigned long count) {
 
 #define __OUTS2(m) \
 if (count) \