mb/google/volteer/variants/drobit: Modify touchpad power sequence

Modify power sequence of touchpad to meet the definition in the spec.

BUG=b:178353432
BRANCH=firmware-volteer-13672.B
TEST=build test firmware and verified by EE team.

Change-Id: I8b8e383223d017223c36044efdf21738fe26d2ea
Signed-off-by: Wayne3 Wang <wayne3_wang@pegatron.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51514
Reviewed-by: Hao Chou <hao_chou@pegatron.corp-partner.google.com>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Zhuohao Lee <zhuohao@google.com>
Reviewed-by: Nick Vaccaro <nvaccaro@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/mainboard/google/volteer/variants/drobit/gpio.c b/src/mainboard/google/volteer/variants/drobit/gpio.c
index b0496af..7e857ea 100644
--- a/src/mainboard/google/volteer/variants/drobit/gpio.c
+++ b/src/mainboard/google/volteer/variants/drobit/gpio.c
@@ -156,6 +156,8 @@
 
 	/* C0  : SMBCLK ==> EN_PP3300_WLAN */
 	PAD_CFG_GPO(GPP_C0, 1, DEEP),
+	/* C13 : UART1_TXD ==> EN_PP5000_TRACKPAD */
+	PAD_CFG_GPO(GPP_C13, 1, DEEP),
 	/* C21 : UART2_TXD ==> H1_PCH_INT_ODL */
 	PAD_CFG_GPI_APIC(GPP_C21, NONE, PLTRST, LEVEL, INVERT),
 	/* C22 : UART2_RTS# ==> PCH_FPMCU_BOOT0 */