msm: kgsl: Capture all the shader data in the snapshot

The shader block size is in dwords. Make sure we copy out all the
bytes that we want.

Change-Id: I42364350ee6314b4830ed11cc06e61d854122543
Signed-off-by: Lynus Vaz <lvaz@codeaurora.org>
Signed-off-by: Archana Obannagari <aobann@codeaurora.org>