OMAP3 clock: don't wait for USBHOST IDLEST bit on usbhost_120m_fclk enable

OMAP3 clock: don't wait for USBHOST IDLEST bit on usbhost_120m_fclk enable

USBHOST on 3430ES2+ has both an initiator and a target CM_IDLEST bit.
Previously, usbhost_48m_fclk enable waited on the wrong bit -- now
fixed.  Also, it appears that USBHOST module readiness (in terms of
CM_IDLEST) only depends on usbhost_48m_fclk and usbhost_iclk.  So
don't wait on usbhost_120m_fck.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>