Makefile: default to cc for host compiler

Since the host compiler might not be gcc but e.g. clang
default to cc/c++ to invoke it.

cc: Masahiro Yamada <yamada.m@jp.panasonic.com>
cc: Tom Rini <trini@ti.com>
Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>

Makefile

@@ -197,8 +197,8 @@ CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
 	  else if [ -x /bin/bash ]; then echo /bin/bash; \
 	  else echo sh; fi ; fi)
 
-HOSTCC       = gcc
-HOSTCXX      = g++
+HOSTCC       = cc
+HOSTCXX      = c++
 HOSTCFLAGS   = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer
 HOSTCXXFLAGS = -O2