The McBSP driver uses virtual clocks to handle enabling and disabling
its hardware clocks.  These virtual clocks have no associated
clockdomain. After commit 60b8b431,
this prevents the McBSP clocks from registering correctly.
Resolve this for the short term by using virt_opp_clkdm for these clocks.
These McBSP virtual clocks should be removed, but such a fix would require
significant changes to the McBSP drivers that would require testing on
OMAP1, 2, and 3 platforms.

Tested on 2430SDP and 3430SDP GP ES2.1.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Eero Nurkkala <ext-eero.nurkkala@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>