disp: msm: dsi: add parsing logic for panel gpio pins/address

Add parsing code for getting the TLMM base address and size
of each GPIO pin register space along with the GPIO pins
used for the specific panel. This list is used to lend
these IO ranges to trusted vm during the trusted UI usecase.

Change-Id: I10429cfa14265d52e898815c6cf94be27daa5677
Signed-off-by: Veera Sundaram Sankaran <veeras@codeaurora.org>