mb/google/hatch: Set SA slow slew rate to 1/2 for jinlon/dratini

Screen flickered on VT2 on some devices  after idle a period of time.

Remove SSR (1/8) setting for SA to default SSR (1/2), screen flicking
issue disappeared, and didn't affect acoustic noise much.

Because CB:38212 (commit eae254e) caused this issue.

BUG=b:160754994
TEST=build dratini, observe that screen flick issue disapppered

Change-Id: I9e81c2f15dd6babfa360eee213fc4ab6310c7455
Signed-off-by: Wisley Chen <wisley.chen@quantatw.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43284
Reviewed-by: Paul Fagerburg <pfagerburg@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/mainboard/google/hatch/variants/dratini/overridetree.cb b/src/mainboard/google/hatch/variants/dratini/overridetree.cb
index 0bada7d..2bfcc26 100644
--- a/src/mainboard/google/hatch/variants/dratini/overridetree.cb
+++ b/src/mainboard/google/hatch/variants/dratini/overridetree.cb
@@ -23,7 +23,6 @@
 	register "AcousticNoiseMitigation" = "1"
 	register "SlowSlewRateForIa" = "2"
 	register "SlowSlewRateForGt" = "2"
-	register "SlowSlewRateForSa" = "2"
 	register "FastPkgCRampDisableIa" = "1"
 	register "FastPkgCRampDisableGt" = "1"
 	register "FastPkgCRampDisableSa" = "1"
diff --git a/src/mainboard/google/hatch/variants/jinlon/overridetree.cb b/src/mainboard/google/hatch/variants/jinlon/overridetree.cb
index a3bb782..fc3bb85 100644
--- a/src/mainboard/google/hatch/variants/jinlon/overridetree.cb
+++ b/src/mainboard/google/hatch/variants/jinlon/overridetree.cb
@@ -23,7 +23,6 @@
 	register "AcousticNoiseMitigation" = "1"
 	register "SlowSlewRateForIa" = "2"
 	register "SlowSlewRateForGt" = "2"
-	register "SlowSlewRateForSa" = "2"
 	register "FastPkgCRampDisableIa" = "1"
 	register "FastPkgCRampDisableGt" = "1"
 	register "FastPkgCRampDisableSa" = "1"