usb: bam: Use correct clocks for SSUSB internal RAM

When using SSUSB private RAM for PIPE memory, ensure
that the RAMs are using the USB3 master clock. This
fixes an issue seen with BAM-to-BAM connections in
SuperSpeed, in which the RAM clocks might get turned
off and halt transfers. The QSCRATCH_CGCTL register
needs to be written during pipe connection to configure
the RAM11-RAM13 clock settings.

Change-Id: I8cd9f73f1922c63a046f5403841fe488beec8f38
Signed-off-by: Jack Pham <jackp@codeaurora.org>