drm/msm/dp: maintain the connector to encoder link during suspend/resume

Avoid disconnecting the connector to encoder link
during suspend in order to maintain the same
connector to encoder state during the resume.

CRs-Fixed: 2327801
Change-Id: I2164c3a9b0e2ecc14c3bb12a53e5da3b2f259212
Signed-off-by: Fuad Hossain <fhossain@codeaurora.org>