MIPS: spinlock: Adjust arch_spin_lock back-off time

Make it similar to the trylock and R10000_LLSC_WAR cases.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9789/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/spinlock.h

@@ -109,7 +109,7 @@ static inline void arch_spin_lock(arch_spinlock_t *lock)
 		"	 subu	%[ticket], %[my_ticket], %[ticket]	\n"
 		"2:							\n"
 		"	.subsection 2					\n"
-		"4:	andi	%[ticket], %[ticket], 0x1fff		\n"
+		"4:	andi	%[ticket], %[ticket], 0xffff		\n"
 		"	sll	%[ticket], 5				\n"
 		"							\n"
 		"6:	bnez	%[ticket], 6b				\n"