ARM: multi_v7_defconfig: Enable serial console on RPi 3

The Raspberry Pi 3 uses the 8250-based auxilary UART of the BCM2837 SoC
as the primary serial console of the board, so enable it in the
multiplatform defconfig.
Signed-off-by: Tuomas Tynkkynen <tuomas@tuxera.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Eric Anholt <eric@anholt.net>

arch/arm/configs/multi_v7_defconfig

@@ -312,6 +312,9 @@ CONFIG_INPUT_ADXL34X=m
 CONFIG_SERIO_AMBAKMI=y
 CONFIG_SERIAL_8250=y
 CONFIG_SERIAL_8250_CONSOLE=y
+CONFIG_SERIAL_8250_EXTENDED=y
+CONFIG_SERIAL_8250_SHARE_IRQ=y
+CONFIG_SERIAL_8250_BCM2835AUX=y
 CONFIG_SERIAL_8250_DW=y
 CONFIG_SERIAL_8250_EM=y
 CONFIG_SERIAL_8250_MT6577=y