usb: phy: qusb: Do not turn off clocks if PMI has vote on it

If PMI called to put DP and DM in floating state, clocks
are needed to configure the PHY in High-Z state.
So, do not turn off the clocks if PMI has vote on it.

Change-Id: If1e3f0e663763f45f0c2188459d897af56a36a72
Signed-off-by: Sriharsha Allenki <sallenki@codeaurora.org>