ALSA: es18xx driver should use udelay error

udelay with more than 20000 may cause __bad_udelay.
Use mdelay for instead.

[fixed a typo spotted by Clemens -- tiwai]

Signed-off-by: Li, Zhen-Hua <zhen-hual@hp.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>