ALSA: emu10k1: Allow to switch hardware sampe rate on EMU

Commit 57e5c630 "emu10k1: allow to
 disable the SRC" force hardware use only one rate (48000 hz).
EMU 0404/1010/1616 have support two hardware sampling rates (44100 and
48000 hz). This patch add check if we have EMU 0404/1010/1616 and
choose correct sample rate to restrict.

Signed-off-by: Mihail Zenkov <mihail.zenkov@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>