drm/i915/cx0: Only clear/set the Pipe Reset bit of the PHY Lanes Owned

drm/i915/cx0: Only clear/set the Pipe Reset bit of the PHY Lanes Owned

Currently, with MFD/pin assignment D, the driver clears the pipe reset bit
of lane 1 which is not owned by display. This causes the display
to block S0iX.

By not clearing this bit for lane 1 and keeping whatever default, S0ix
started to work. This is already what the driver does at the end
of the phy lane reset sequence (Step#8)

Bspec: 65451
Fixes: 619a06dba6fa ("drm/i915/mtl: Reset only one lane in case of MFD")
Cc: Mika Kahola <mika.kahola@intel.com>
Cc: Gustavo Sousa <gustavo.sousa@intel.com>
Signed-off-by: Khaled Almahallawy <khaled.almahallawy@intel.com>
Reviewed-by: Gustavo Sousa <gustavo.sousa@intel.com>
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231005001310.154396-1-khaled.almahallawy@intel.com