ARC: [plat-eznps] spinlock aware for MTM

This way when we execute "ex" during trying to hold lock we can switch to
other HW thread and utilize the core intead of just spinning on a lock.

We noticed about 10% improvement of execution time with hackbench test.
Signed-off-by: NNoam Camus <noamca@mellanox.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

arch/arc/include/asm/spinlock.h

@@ -252,9 +252,15 @@ static inline void arch_spin_lock(arch_spinlock_t *lock)
 
 	__asm__ __volatile__(
 	"1:	ex  %0, [%1]		\n"
+#ifdef CONFIG_EZNPS_MTM_EXT
+	"	.word %3		\n"
+#endif
 	"	breq  %0, %2, 1b	\n"
 	: "+&r" (val)
 	: "r"(&(lock->slock)), "ir"(__ARCH_SPIN_LOCK_LOCKED__)
+#ifdef CONFIG_EZNPS_MTM_EXT
+	, "i"(CTOP_INST_SCHD_RW)
+#endif
 	: "memory");
 
 	/*