sh_keysc: remove request_mem_region() and release_mem_region()

Remove request_mem_region() and release_mem_region() from sh_keysc driver.
Those functions can find resource conflict, but it is already checked in
platform_device_add().

Signed-off-by: Tetsuya Mukawa <mukawa@igel.co.jp>
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>