sh: Add -mno-fdpic to default flags.

Presently the --fdpic specifier and the --isa matching clash when
building with FDPIC toolchains. As we have no interest in building the
kernel with --fdpic in the first place, always try to add in -mno-fdpic
to the default flags.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/Makefile

@@ -41,6 +41,8 @@ cflags-$(CONFIG_CPU_SH5)		:= $(call cc-option,-m5-32media-nofpu,)
 cflags-$(CONFIG_CPU_BIG_ENDIAN)		+= -mb
 cflags-$(CONFIG_CPU_LITTLE_ENDIAN)	+= -ml
 
+cflags-y	+= $(call cc-option,-mno-fdpic)
+
 #
 # -Wa,-isa= tuning implies -Wa,-dsp for the versions of binutils that
 # support it, while -Wa,-dsp by itself limits the range of usable opcodes