serial: sh: Add R-Car Gen4 support

Add R-Car Gen4 family support. The basic function is as same as previous
R-Car Generation.

Reviewed-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Signed-off-by: Hai Pham <hai.pham.ud@renesas.com>
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
[Marek: Swap RZ/A1 and Gen4 to keep the GenN sequence, use RCAR_64]
diff --git a/drivers/serial/serial_sh.h b/drivers/serial/serial_sh.h
index eb8523d..128b077 100644
--- a/drivers/serial/serial_sh.h
+++ b/drivers/serial/serial_sh.h
@@ -89,7 +89,7 @@
 # define SCSPTR7 0xe800a820 /* 16 bit SCIF */
 # define SCSCR_INIT(port)	0x38 /* TIE=0,RIE=0,TE=1,RE=1,REIE=1 */
 # define SCIF_ORER 0x0001  /* overrun error bit */
-#elif defined(CONFIG_RCAR_GEN2) || defined(CONFIG_RCAR_GEN3) || \
+#elif defined(CONFIG_RCAR_GEN2) || defined(CONFIG_RCAR_64) || \
       defined(CONFIG_R7S72100)
 # if defined(CFG_SCIF_A)
 #  define SCIF_ORER	0x0200