UBUNTU: SAUCE: (no-up) fix highbank include path

Continue to carry as its not hurting anything. Of course I could just
build test without this patch, but thats a giant pain.
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

arch/arm/mach-highbank/Makefile

+KBUILD_CFLAGS += -I$(srctree)/arch/arm/mach-highbank/include
+
 obj-y					:= highbank.o system.o smc.o
 
 plus_sec := $(call as-instr,.arch_extension sec,+sec)