Cave: Add override for JTAG to UART for USBPD

Enable access to USBPD on cave boards.

BUG=chrome-os-partner:50971
BRANCH=TOT
TEST=none

Change-Id: If34387bd7faf07e67713926975e77f78efdb9de6
Signed-off-by: Zhuo-hao Lee <zhuo-hao.lee@intel.com>
Reviewed-on: https://chromium-review.googlesource.com/333825
Reviewed-by: Shawn N <shawnn@chromium.org>
diff --git a/servo/servo_interfaces.py b/servo/servo_interfaces.py
index f88f623..a579bb5 100644
--- a/servo/servo_interfaces.py
+++ b/servo/servo_interfaces.py
@@ -137,6 +137,9 @@
 INTERFACE_BOARDS['strago'][0x18d1][0x5002][0] = 'ftdi_uart'
 
 # Skylake boards re-purpose JTAG to be UART
+INTERFACE_BOARDS['cave'][0x18d1][0x5002] = \
+    list(INTERFACE_DEFAULTS[0x18d1][0x5002])
+INTERFACE_BOARDS['cave'][0x18d1][0x5002][0] = 'ftdi_uart'
 INTERFACE_BOARDS['chell'][0x18d1][0x5002] = \
     list(INTERFACE_DEFAULTS[0x18d1][0x5002])
 INTERFACE_BOARDS['chell'][0x18d1][0x5002][0] = 'ftdi_uart'