include/linux/genalloc.h: spinlock_t needs spinlock_types.h

Compiling a C file which includes genalloc.h but without
spinlock_types.h being included before, we will see the compile error
below.

include/linux/genalloc.h:54:2: error: unknown type name `spinlock_t'

Include spinlock_types.h from genalloc.h to fix the problem.

Signed-off-by: Shawn Guo <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

include/linux/genalloc.h

···
 #ifndef __GENALLOC_H__
 #define __GENALLOC_H__
 
+#include <linux/spinlock_types.h>
+
 struct device;
 struct device_node;