kgsl/drm: Remove dependency with kgsl-drm.

This patch removes dependency with kgsl-drm for irq feature enable.
I seperate kgsl-drm from kgsl for platform device.

Change-Id: I42f55c2e8ef0f8a519c887c07c200131c62d4e22
Signed-off-by: Eunchul Kim <chulspro.kim@samsung.com>
Signed-off-by: Mathew Karimpanal <kjmathew@codeaurora.org>
(cherry picked from commit 8388d11b32f36730d6a7ab09c243647bec6baa81)
[lvaz@codeaurora.org: resolve trivial merge conflict]
Signed-off-by: Lynus Vaz <lvaz@codeaurora.org>