sh: No need to explicitly include <linux/rwlock.h>.

Since <linux/spinlock.h> already includes <linux/rwlock.h>, and the
latter file will warn about not having included the former file
anyway, there is no value in including rwlock.h explicitly.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/mm/pmb.c

@@ -23,7 +23,6 @@
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/spinlock.h>
-#include <linux/rwlock.h>
 #include <asm/sizes.h>
 #include <asm/system.h>
 #include <asm/uaccess.h>