memory: emif: Use DEFINE_SPINLOCK() for spinlock

Spinlock can be initialized automatically with DEFINE_SPINLOCK() rather
than explicitly calling spin_lock_init().

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Link: https://lore.kernel.org/r/20201228135056.28511-1-zhengyongjun3@huawei.com


Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>