mb/google/brya/var/vell: Set GPP_B2 NC for RGB keybaord

When GPP_B2 output high, there is a leakage path. This patch fix it by
setting the pin NC.

BUG=b:233959105
BRANCH=firmware-brya-14505.B
TEST=emerge-brya coreboot

Change-Id: I3c833d5d62c715960dcb27494a0b9b93c91e8f2f
Signed-off-by: Robert Chen <robert.chen@quanta.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/66382
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nick Vaccaro <nvaccaro@google.com>

src/mainboard/google/brya/variants/vell/gpio.c

@@ -11,7 +11,7 @@ static const struct pad_config override_gpio_table[] = {
 	PAD_NC(GPP_A11, NONE),
 
 	/* B2  : VRALERT# ==> RGB_RST_ODL */
-	PAD_CFG_GPO_LOCK(GPP_B2, 1, LOCK_CONFIG),
+	PAD_NC(GPP_B2, NONE),
 	/* B15  : TIME_SYNC0 ==> NC */
 	PAD_NC_LOCK(GPP_B15, NONE, LOCK_CONFIG),