clk: qcom-scuba: Add support for USB BCR

USB client would require to request for USB BCR,
so add support for same. Also update configuration
for gpll8 and SLEW support is added for gpll11.

Change-Id: I9af75b00226614b4942203776b5dfe83a85ca8ee
Signed-off-by: Naveen Yadav <naveenky@codeaurora.org>