nivviks/usbc: enable vbus voltage monitoring

RAA489000 tcpc shows TCPC_REG_VBUS_VOLTAGE register
value as zero always. Set bit in tcpc_config flags
to enable vbus voltage reporting by tcpc.
This will help to debug issues related to USB-C VBUS
voltage.

BUG=b:219891340
BRANCH=none
TEST=TCPC RAA489000 reports measured vbus voltage in
	TCPC_REG_VBUS_VOLTAGE register.

Change-Id: Ifa95132a9646e318b3734ab6b012de76adf47d79
Signed-off-by: Deepti Deshatty <[email protected]>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3476655
Reviewed-by: Diana Z <[email protected]>

Author: Deepti Deshatty

zephyr/projects/nissa/src/nivviks/usbc.c

@@ -26,7 +26,8 @@ struct tcpc_config_t tcpc_config[CONFIG_USB_PD_PORT_MAX_COUNT] = {
 		},
 		.drv = &raa489000_tcpm_drv,
 		/* RAA489000 implements TCPCI 2.0 */
-		.flags = TCPC_FLAGS_TCPCI_REV2_0,
+		.flags = TCPC_FLAGS_TCPCI_REV2_0 |
+			TCPC_FLAGS_VBUS_MONITOR,
 	},
 	{ /* sub-board */
 		.bus_type = EC_BUS_TYPE_I2C,
@@ -36,7 +37,8 @@ struct tcpc_config_t tcpc_config[CONFIG_USB_PD_PORT_MAX_COUNT] = {
 		},
 		.drv = &raa489000_tcpm_drv,
 		/* RAA489000 implements TCPCI 2.0 */
-		.flags = TCPC_FLAGS_TCPCI_REV2_0,
+		.flags = TCPC_FLAGS_TCPCI_REV2_0 |
+			TCPC_FLAGS_VBUS_MONITOR,
 	},
 };