mb/google/volteer/var/volteer: I2C5 trackpad bus freq 400 kHz

The current I2C5 bus frequency is 367 kHZ, which does not meet the spec.
This change updates scl_lcnt, scl_hcnt, scl_hcnt value for I2C5 to bring
the bus frequency closer to 400kHz.

BUG=b:153588771
TEST=Verified that I2C5 frequency is between 389-396kHz.
Signed-off-by: Johnny Li <johnny_li@wistron.corp-partner.google.com>
Change-Id: If59502aec7c3ab55864a518d626cde52aee18373
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43746
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Caveh Jalali <caveh@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/volteer/variants/volteer/overridetree.cb

@@ -1,5 +1,48 @@
 chip soc/intel/tigerlake
 	register "SaGv" = "SaGv_Disabled"
+	#+-------------------+---------------------------+
+	#| Field             |  Value                    |
+	#+-------------------+---------------------------+
+	#| chipset_lockdown  | CHIPSET_LOCKDOWN_COREBOOT |
+	#| GSPI0             | cr50 TPM. Early init is   |
+	#|                   | required to set up a BAR  |
+	#|                   | for TPM communication     |
+	#|                   | before memory is up       |
+	#| GSPI1             | Fingerprint MCU           |
+	#| I2C0              | Audio                     |
+	#| I2C1              | Touchscreen               |
+	#| I2C2              | WLAN, SAR0                |
+	#| I2C3              | Camera, SAR1              |
+	#| I2C5              | Trackpad                  |
+	#+-------------------+---------------------------+
+	register "common_soc_config" = "{
+		.chipset_lockdown = CHIPSET_LOCKDOWN_COREBOOT,
+		.gspi[0] = {
+			.speed_mhz = 1,
+			.early_init = 1,
+		},
+		.i2c[0] = {
+			.speed = I2C_SPEED_FAST,
+		},
+		.i2c[1] = {
+			.speed = I2C_SPEED_FAST,
+		},
+		.i2c[2] = {
+			.speed = I2C_SPEED_FAST,
+		},
+		.i2c[3] = {
+			.speed = I2C_SPEED_FAST,
+		},
+		.i2c[5] = {
+			.speed = I2C_SPEED_FAST,
+			.speed_config[0] = {
+				.speed = I2C_SPEED_FAST,
+				.scl_lcnt = 163,
+				.scl_hcnt = 75,
+				.sda_hold = 36,
+			},
+		},
+	}"
 	device domain 0 on
 		device pci 15.0 on
 			chip drivers/i2c/generic