[ARM] Add linux/compiler.h includes where required

atomic.h, bitops.h and mmu_context.h are using likely/unlikely.
thread_info.h uses __attribute_const__.  Hence these files require
linux/compiler.h to be included.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/include/asm-arm/thread_info.h b/include/asm-arm/thread_info.h
index 8252a4c..7c98557 100644
--- a/include/asm-arm/thread_info.h
+++ b/include/asm-arm/thread_info.h
@@ -12,6 +12,7 @@
 
 #ifdef __KERNEL__
 
+#include <linux/compiler.h>
 #include <asm/fpstate.h>
 
 #define THREAD_SIZE_ORDER	1