disp: msm: dp: skip HPD connect notification if IRQ HPD is pending

Upon completing the link setup, check to see if any IRQ HPD
notification is pending prior to sending the connect notification
to the user mode. If an IRQ HPD is pending, address the IRQ first
prior to sending the notification. This will ensure that the link
setup is stable first before the connection setup is started. This
will also help in adhering to the CTS timing requirements for
responding to IRQ HPD notifications. The current patchset limits
this logic only for SST connections.

CRs-Fixed: 2565704
Change-Id: I3f5e8e9290f915b98ec5e9e6cf9ff14aa9929d96
Signed-off-by: Aravind Venkateswaran <aravindh@codeaurora.org>