msm: kgsl: Remove sscanf() from kgsl_pwrctrl.c

Replace sscanf() in kgsl_pwrctrl.c with a generic function to safely
convert 32 bit unsigned ints.

CRs-fixed: 563585
Change-Id: Ic0dedbad10e2264ec8fccab622d094d123b49b77
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
msm: kgsl: don't use sscanf()

Friends do not let friends use sscanf().

CRs-Fixed: 563605
Change-Id: Ic0dedbad56af5bbee4fc833701d8bc93b118efa9
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Ananta Kishore K <akollipa@codeaurora.org>