tty: serial: samsung: Fix serial rx on Apple A7-A9

tty: serial: samsung: Fix serial rx on Apple A7-A9

Apple's older A7-A9 SoCs seems to use bit 3 in UTRSTAT as RXTO, which is
enabled by bit 11 in UCON.

Access these bits in addition to the original RXTO and RXTO enable bits,
to allow serial rx to function on A7-A9 SoCs. This change does not
appear to affect the A10 SoC and up.

Tested-by: Janne Grunau <j@jannau.net>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Signed-off-by: Nick Chan <towinchenmi@gmail.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20240911050741.14477-4-towinchenmi@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>