sdm: Set system property when HDMI is Primary

Set a system property "persist.sys.is_hdmi_primary" to indicate
that the HDMI interface is the primary display. This property can
be used by other system components to determine whether to
trigger certain functionality when HDMI is primary.

CRs-Fixed: 1009711
Change-Id: Id215a6ee9c6aa2953b0e2c01af0bad035b728a46
6 files changed