mb/google/rex/var/kanix: Tune camera I2C timing

1. frequency changes to 366 kHz from 457 kHz
2. tHIGH changes to 0.8 us from 0.514 us
3. tSU:STA changes to 0.68 us from 0.56 us

BUG=b:417375114
BRANCH=firmware-rex-15709.B
TEST=1.emerge-rex coreboot chromeos-bootimage
     2.EA is measured and verified by HW
Change-Id: I996885a9acf2eea7f49ecf2fcd4f7d3fda842c8e
Signed-off-by: Kenneth Chan <kenneth.chan@quanta.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/87580
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: David Wu <david_wu@quanta.corp-partner.google.com>
Reviewed-by: Subrata Banik <subratabanik@google.com>

src/mainboard/google/rex/variants/kanix/overridetree.cb

@@ -140,7 +140,12 @@ chip soc/intel/meteorlake
 			.speed = I2C_SPEED_FAST,
 			.rise_time_ns = 900,
 			.fall_time_ns = 400,
-			.data_hold_time_ns = 50,
+			.speed_config[0] = {
+				.speed = I2C_SPEED_FAST,
+				.scl_lcnt = 163,
+				.scl_hcnt = 85,
+				.sda_hold = 40,
+			}
 		},
 	}"