ARM: bcm2385_defconfig: Enable BT support for BCM43438

The Raspberry Pi Zero W has an onboard BT chip (BCM43438). So enable the
necessary HCI UART driver (requires serial device bus).
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

arch/arm/configs/bcm2835_defconfig

@@ -49,6 +49,9 @@ CONFIG_IP_PNP=y
 CONFIG_IP_PNP_DHCP=y
 CONFIG_NETWORK_SECMARK=y
 CONFIG_NETFILTER=y
+CONFIG_BT=y
+CONFIG_BT_HCIUART=m
+CONFIG_BT_HCIUART_BCM=y
 CONFIG_CFG80211=y
 CONFIG_MAC80211=y
 CONFIG_DEVTMPFS=y
@@ -74,6 +77,7 @@ CONFIG_SERIAL_8250_SHARE_IRQ=y
 CONFIG_SERIAL_8250_BCM2835AUX=y
 CONFIG_SERIAL_AMBA_PL011=y
 CONFIG_SERIAL_AMBA_PL011_CONSOLE=y
+CONFIG_SERIAL_DEV_BUS=y
 CONFIG_TTY_PRINTK=y
 CONFIG_I2C_CHARDEV=y
 CONFIG_I2C_BCM2835=y