msm: kgsl: use of_find_node_by_name() instead of rolling our own

For some reason we thought it would be a good idea to make a weak
version of of_find_node_by_name() instead of actually using
of_find_node_by_name().

Change-Id: Ic0dedbad317092aaa0922c4ffaca7ca7e83398e2
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>