msm: kgsl: Move secvid programming to gpudev

Since eCP will need these register writes as well, instead
of exporting a function set_secvid, move these register writes
to respective target specific functions which are common to
both eCP enabled and disabled configurations. This also helps
get rid of the register offset definitions.

Change-Id: I2faa996901c746e7277dc2fdc272b9eb76e13e9c
Signed-off-by: Harshdeep Dhatt <hdhatt@codeaurora.org>