qseecom: fix an error related to app name comparision

Make changes to use strcmp to compare app name, and
avoid the memcpy comparision error if the first
several chars of an app name is exactly equal to
another app name. Besides, on some targets, keymaster
app may be first loaded as "keymaste" by qseecomd,
and then used as "keymaster". To avoid checking app
name error, register "keymaster" into app_list and
thread private data.

Change-Id: I468b4e5cb1d5d77ac5d687d0bddc8614b972785f
Signed-off-by: Zhen Kong <zkong@codeaurora.org>