alsa_sound: Update the usecase before enabling device

When speaker device is selected, route function enables
the TX processing path for speaker protection.
Change fixes issue where opendevice and route function try to
enable verbs for ucm usecase set function.As per UCM specification
only one verb should be active any time.

Change-Id: I9619ece0be9e1e2823321d341363470b1812d8eb