msm: sde: update check flags to handle CONFIG_DEBUG_FS

Add support to handle disabling of CONFIG_DEBUG_FS.

Change-Id: I8c07434afc36edfae9bd9bc7880d07264eca7650
Signed-off-by: Krishna Manikandan <mkrishn@codeaurora.org>
[rshaha@codeaurora.org: resolve trivial merge conflicts]
Signed-off-by: Rahul Shahare <rshaha@codeaurora.org>