drm/msm: move msm notify functon from msm to soc

Move msm notify helper functions from msm to soc to make sure
the function is valid if DRM MSM is not compiled.

Also add MSM_DRM_TECHPACK option to select dependent modules
that are selected by DRM MSM. This will allow defconfig to
have the flexibility to select builtin DRM MSM or external
techpack.

Change-Id: I6b0cc8f31b5c185907683c6347e5a594fa2101ad
Signed-off-by: Xiaowen Wu <wxiaowen@codeaurora.org>