ARC: Abstract out ISA specific SLEEP args

No semantical changes, prepares for ARCv2 specific change in next commit

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/kernel/process.c

@@ -44,11 +44,10 @@ SYSCALL_DEFINE0(arc_gettls)
 void arch_cpu_idle(void)
 {
 	/* sleep, but enable all interrupts before committing */
-	if (is_isa_arcompact()) {
-		__asm__("sleep 0x3");
-	} else {
-		__asm__("sleep 0x10");
-	}
+	__asm__ __volatile__(
+		"sleep %0	\n"
+		:
+		:"I"(ISA_SLEEP_ARG)); /* can't be "r" has to be embedded const */
 }
 
 asmlinkage void ret_from_fork(void);