kohaku: Modify TCPC register MUX_DP_EQ_Configuration setting on MB port.
kohaku: Modify TCPC register MUX_DP_EQ_Configuration setting on MB port.

Modify TCPC register MUX_DP_EQ_Configuration setting to 0x98 on MB
port.

BUG=b:149876123
BRANCH=master,hatch
TEST=Observed flashing on external monitor prior to fix and didn't
     observe flashing after applying the fix.

Change-Id: I4c19f8211b141ab8726cfa8b6eacb93ad9587705
Signed-off-by: Shelley Chen <ab7b8cc85923339aed379eb1c5cc4dccfd2eb3d7@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2067480
Reviewed-by: Aseda Aboagye <12c9b286316a940fd31c24070da5ab64cdd4d0e7@chromium.org>
Reviewed-by: Tim Wawrzynczak <86444811eee8c2cb29e29a251d7a069e64ccc665@chromium.org>
Commit-Queue: Shelley Chen <ab7b8cc85923339aed379eb1c5cc4dccfd2eb3d7@chromium.org>
Tested-by: Shelley Chen <ab7b8cc85923339aed379eb1c5cc4dccfd2eb3d7@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec