[ALSA] ymfpci: change timer resolution to 48 kHz

Modules: YMFPCI driver

We better pretend that the ymfpci timer runs at 48 kHz because the
interrupt frequency cannot be higher, and clients that would try to
use 96 kHz would run at half their desired speed.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>