mb/google/skyrim/var/frostflow: Update I2C setting for touchpad

Update setting for touchpad I2C frequency and hold time to meet touchpad
i2c SPEC.
- Frequency: 380 ~ 400 kHz
- hold time : 0.3 ~ 0.9 us

BUG=b:261159229
TEST=On frostflow, touchpad i2c spec from EE measure
Frequencies: I2C0 (Touchpad): 393.7 kHz
Hold time = 0.604 us

Change-Id: Iecf4960a12aa56ac307fb9022e47c4e94a2551c1
Signed-off-by: Rex Chou <rex_chou@compal.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/72114
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/skyrim/variants/frostflow/overridetree.cb

@@ -22,7 +22,8 @@ chip soc/amd/mendocino
 		.speed_config[0] = {
 			.speed = I2C_SPEED_FAST,
 			.scl_hcnt = 120,
-			.scl_lcnt = 215,
+			.scl_lcnt = 220,
+			.sda_hold = 90,
 		}
 	}"