pil: soc: qcom: Add Documentation for mss_pdc_offset

Add documentation for new PIL DT entry which specifies which bit in the PDC
SYNC register corresponds to the modem.

Change-Id: I9b792c7853407911b226b61005e5266fc100e52f
Signed-off-by: Kyle Yan <kyan@codeaurora.org>
1 file changed