tty: serial: samsung_tty: Fix suspend/resume on S5L

We were restoring the IRQ masks then clearing them again, because
ucon_mask wasn't set properly. Adding that makes suspend/resume
work as intended.
Signed-off-by: Hector Martin <marcan@marcan.st>
Link: https://lore.kernel.org/r/20220502092505.30934-1-marcan@marcan.stSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/samsung_tty.c

@@ -2826,6 +2826,7 @@ static const struct s3c24xx_serial_drv_data s5l_serial_drv_data = {
 		.num_clks	= 1,
 		.clksel_mask	= 0,
 		.clksel_shift	= 0,
+		.ucon_mask	= APPLE_S5L_UCON_MASK,
 	},
 	.def_cfg = {
 		.ucon		= APPLE_S5L_UCON_DEFAULT,

include/linux/serial_s3c.h

@@ -256,6 +256,9 @@
 #define APPLE_S5L_UCON_DEFAULT		(S3C2410_UCON_TXIRQMODE | \
 					 S3C2410_UCON_RXIRQMODE | \
 					 S3C2410_UCON_RXFIFO_TOI)
+#define APPLE_S5L_UCON_MASK		(APPLE_S5L_UCON_RXTO_ENA_MSK | \
+					 APPLE_S5L_UCON_RXTHRESH_ENA_MSK | \
+					 APPLE_S5L_UCON_TXTHRESH_ENA_MSK)
 
 #define APPLE_S5L_UTRSTAT_RXTHRESH	(1<<4)
 #define APPLE_S5L_UTRSTAT_TXTHRESH	(1<<5)