serial: 8250_em: Fix UART port type

stable inclusion
from stable-v5.10.176
commit 0c16c20b87873801d6eaa79e5a150eadab9145b3
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8CHVQ

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=0c16c20b87873801d6eaa79e5a150eadab9145b3



--------------------------------

commit 32e293be upstream.

As per HW manual for  EMEV2 "R19UH0040EJ0400 Rev.4.00", the UART
IP found on EMMA mobile SoC is Register-compatible with the
general-purpose 16750 UART chip. Fix UART port type as 16750 and
enable 64-bytes fifo support.

Fixes: 22886ee9 ("serial8250-em: Emma Mobile UART driver V2")
Cc: stable@vger.kernel.org
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230227114152.22265-2-biju.das.jz@bp.renesas.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>