EHCI: HSIC: Allow standalone power collapse when HSIC is active

HSIC generates interrupt at 4ms interval. If idle power collapse
is enabled when HSIC is active, krait keeps on going into idle
power collapse requesting RPM to handle the sleep set requirement.
If HSIC interrupt comes after 4ms interval, krait comes out of idle
power collapse and it again ask RPM to handle this request therefore
keeps RPM busy handling requests due to frequent idle power collapse.
This has a power impact. Hence only allow standalone power collapse
when HSIC is active to avoid RPM involvement in assisting kraits to
power collapse. Vote for idle power collapse when HSIC goes to low
power mode.

Change-Id: Iee8bc1fa180499f2d26fbac955a6a6ed767fdeb4
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>