mb/google/volteer/variants/volteer2: Tune I2C3 camera bus freq 400 kHz

The current I2C3 bus frequency is 341 kHZ, which does not meet the spec.
This change updates scl_lcnt, scl_hcnt, sda_hold value for I2C3 to bring
the bus frequency closer to 400kHz.

BUG=b:153588771
TEST=Verified that I2C3 frequency is 394kHz.

Signed-off-by: Johnny Li <johnny_li@wistron.corp-partner.google.com>
Change-Id: Ie1ef95bb39d71fbb113120a0ec88305bc23e7ab9
Reviewed-on: https://review.coreboot.org/c/coreboot/+/47225
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Caveh Jalali <caveh@chromium.org>

src/mainboard/google/volteer/variants/volteer2/overridetree.cb

@@ -39,6 +39,12 @@ chip soc/intel/tigerlake
 		},
 		.i2c[3] = {
 			.speed = I2C_SPEED_FAST,
+			.speed_config[0] = {
+				.speed = I2C_SPEED_FAST,
+				.scl_lcnt = 153,
+				.scl_hcnt = 75,
+				.sda_hold = 36,
+			},
 		},
 		.i2c[5] = {
 			.speed = I2C_SPEED_FAST,