ARC: make write_aux_reg safer against macro substitution

It was generating warnings when called as write_aux_reg(x, paddr >> 32)
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/include/asm/arcregs.h

@@ -120,7 +120,7 @@
 
 /* gcc builtin sr needs reg param to be long immediate */
 #define write_aux_reg(reg_immed, val)		\
-		__builtin_arc_sr((unsigned int)val, reg_immed)
+		__builtin_arc_sr((unsigned int)(val), reg_immed)
 
 #else