meta-facebook: minerva: enable USB UART config

Enable USB UART configuration for smart valve implementation.

Change-Id: I1032c9b4ff078b74168a6f47a0b428b3eb72d7e7
Signed-off-by: Yang Chen <yang.chen@quantatw.com>
diff --git a/meta-facebook/meta-minerva/recipes-kernel/linux/linux-aspeed/minerva.cfg b/meta-facebook/meta-minerva/recipes-kernel/linux/linux-aspeed/minerva.cfg
index 7672eb6..02ce902 100644
--- a/meta-facebook/meta-minerva/recipes-kernel/linux/linux-aspeed/minerva.cfg
+++ b/meta-facebook/meta-minerva/recipes-kernel/linux/linux-aspeed/minerva.cfg
@@ -33,3 +33,8 @@
 
 # RTC
 CONFIG_RTC_DRV_PCF8563=y
+
+# USB UART
+CONFIG_USB_SERIAL=y
+CONFIG_USB_SERIAL_CONSOLE=y
+CONFIG_USB_SERIAL_FTDI_SIO=y