ALSA: ens1371: fix Creative Ectiva support

To make the EV1938 chip work, add a magic bit and an extra delay.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Tested-by: Tino Schmidt <mailtinoshomepage@gmx.net>
Cc: all 2.6.x <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>