ARC: Introduce is_isa_X() functions

Introduce is_isa_arcv2() and is_isa_arcompact() functions.

These functions only check configuration options and return
compile-time constant so they can be used instead of #ifdef's to
to write cleaner code.

Now we can write:
-------------->8---------------
if (is_isa_arcv2())
	ioc_configure();
-------------->8---------------
instead of:
-------------->8---------------
ifdef CONFIG_ISA_ARCV2
	ioc_configure();
endif
-------------->8---------------

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

arch/arc/include/asm/arcregs.h

@@ -8,6 +8,7 @@
 #define _ASM_ARC_ARCREGS_H
 
 #include <asm/cache.h>
+#include <config.h>
 
 /*
  * ARC architecture has additional address space - auxiliary registers.
@@ -88,6 +89,16 @@
 
 /* ARCNUM [15:8] - field to identify each core in a multi-core system */
 #define CPU_ID_GET()	((read_aux_reg(ARC_AUX_IDENTITY) & 0xFF00) >> 8)
+
+static const inline int is_isa_arcv2(void)
+{
+	return IS_ENABLED(CONFIG_ISA_ARCV2);
+}
+
+static const inline int is_isa_arcompact(void)
+{
+	return IS_ENABLED(CONFIG_ISA_ARCOMPACT);
+}
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_ARC_ARCREGS_H */