nds32: define __NDS32_E[BL]__ for sparse

nds32 depends on the macros '__NDS32_E[BL]__' to correctly
select or define endian-specific macros, structures or pieces
of code.

These macros are predefined by the compiler but sparse knows nothing
about them and thus may pre-process files differently from what
GCC would.

Fix this by adding '-D__NDS32_E[BL]__' to CHECKFLAGS.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Acked-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>

arch/nds32/Makefile

@@ -34,10 +34,12 @@ ifdef CONFIG_CPU_LITTLE_ENDIAN
 KBUILD_CFLAGS   += $(call cc-option, -EL)
 KBUILD_AFLAGS   += $(call cc-option, -EL)
 LDFLAGS         += $(call cc-option, -EL)
+CHECKFLAGS      += -D__NDS32_EL__
 else
 KBUILD_CFLAGS   += $(call cc-option, -EB)
 KBUILD_AFLAGS   += $(call cc-option, -EB)
 LDFLAGS         += $(call cc-option, -EB)
+CHECKFLAGS      += -D__NDS32_EB__
 endif
 
 boot := arch/nds32/boot