tty: serial: ma35d1_serial: Add missing check for ioremap

Add check for ioremap() and return the error if it fails in order to
guarantee the success of ioremap().

Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Acked-by: Jacky Huang <ychuang3@nuvoton.com>
Link: https://lore.kernel.org/r/20230915071106.3347-1-nichen@iscas.ac.cn


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