HDCP TZ module: query for HDCP 1.4 SW keys

Implement API for starting app and setting
keys through QSEECom. This allows compatible
hardware to use SW HDCP keys instead of
fused keys.

Change-Id: Ia70cf4b4695040973f61449569798be106748fef
Signed-off-by: Casey Piper <cpiper@codeaurora.org>