clk: qcom: gcc-lahaina: Add USB force_mem_core_on clocks

The FORCE_MEM_CORE_ON bits default to 0 and this is fine for most use
cases. However, USB needs FORCE_MEM_CORE_ON=1 to properly retain its
memories when USB APM switches from CX to MX. This can't just be a
one-time setting since the FORCE_MEM_CORE_ON bits need to be set/cleared
upon USB cable connect/disconnect for power optimization. Add fake
clocks to allow the USB client to control them.

Change-Id: Ic7aac944feaa6a956a8892e0cf1f4dd465659302
Signed-off-by: Mike Tipton <mdtipton@codeaurora.org>