hwspinlock: sprd: fixed warning of unused variable 'sprd_hwspinlock_of_match'

The macro function of_match_ptr() is NULL if CONFIG_OF is not set, in this
case Clang compiler would complain the of_device_id variable is unused.

Reviewed-by: Baolin Wang <[e-mail]>
Reported-by: kernel test robot <[e-mail]>
Fixes: d8c8bbbb1aba ("hwspinlock: sprd: Add hardware spinlock driver")
Signed-off-by: Chunyan Zhang <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Bjorn Andersson <[e-mail]>

drivers/hwspinlock/sprd_hwspinlock.c

···
 	.probe = sprd_hwspinlock_probe,
 	.driver = {
 		.name = "sprd_hwspinlock",
-		.of_match_table = of_match_ptr(sprd_hwspinlock_of_match),
+		.of_match_table = sprd_hwspinlock_of_match,
 	},
 };
 module_platform_driver(sprd_hwspinlock_driver);