arm64: defconfig: Enable SERIAL_8250_OMAP

Enabling CONFIG_SERIAL_8250_OMAP that is used by TI's
AM6 SoC.
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Acked-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm64/configs/defconfig

@@ -289,6 +289,7 @@ CONFIG_SERIAL_8250_EXTENDED=y
 CONFIG_SERIAL_8250_SHARE_IRQ=y
 CONFIG_SERIAL_8250_BCM2835AUX=y
 CONFIG_SERIAL_8250_DW=y
+CONFIG_SERIAL_8250_OMAP=y
 CONFIG_SERIAL_8250_MT6577=y
 CONFIG_SERIAL_8250_UNIPHIER=y
 CONFIG_SERIAL_OF_PLATFORM=y