sdm: Wait for uevent_init() to complete to enable HPD.

Enable HPD for external display after the successfull completion of
uevent_init() in uevent thread to avoid HDMI connect/disconnect events
getting missed during bootup.

Change-Id: I40fd0afd482cb26e0d6da90942ecf40dda832f48
CRs-Fixed: 2025830
2 files changed