drm/msm/sde: add preliminary debugfs support

Debugfs additions under /sys/kernel/debug/dri/0.

Add sde_debugfs_setup_regset32()/sde_debugfs_create_regset32()
for creating register dump debugfs files, and add initial debugfs
support in plane driver.

Change-Id: I7e0a368fbcf6a249a016d2224c01666fe51abae9
Signed-off-by: Clarence Ip <cip@codeaurora.org>
16 files changed