ARM: dts: msm: remove unused entries for DisplayPort on sm8150

Remove unused GPIO entries as they are not relevant to DisplayPort
functionality on the sm8150 target.

CRs-Fixed: 2331318
Change-Id: If92850d4123b906a8f04612a17ca0bb558347414
Signed-off-by: Tatenda Chipeperekwa <tatendac@codeaurora.org>