[ALSA] ac97 - fix microphone and line_in selection logic

This patch fixes the Microphone and LINE_IN select logic for
Analog Devices surround codecs with shared jacks.  The existing
code can never utilize the shared jacks for Microphone and LINE_IN
due to the reversed jack selection logic.  The patched code
correctly selects the shared jack for input if the 'Channel Mode'
selector does not specify that the jack is to be used for output.
Specifically, in '2ch' mode the Center/LFE jack is used for
microphone input and the Surround jack is used for LINE_IN,
in '4ch' mode the Center/LFE jack is used for microphone input
and the Surround jack is used for output, and in '6ch' mode
both jacks are used for output.

Signed-off-by: Randy Cushman <rcushman_linux@earthlink.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>