tty: serial: meson: Use devm_ioremap_resource to get register mapped memory

Replace devm_request_mem_region and devm_ioremap with
devm_ioremap_resource to make the code cleaner.

Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Yu Tu <yu.tu@amlogic.com>
Link: https://lore.kernel.org/r/20220225073922.3947-3-yu.tu@amlogic.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>