ALSA: hda - Fix missing module loading with model=generic option

When the generic codec driver is specified via model option or such,
the hda driver doesn't try to load the generic driver module but still
loads the codec-specific driver, and this ends up with the binding
failure.

This patch fixes it by moving the generic module request in the common
helper code.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111021
Cc: <stable@vger.kernel.org> # v4.4+
Signed-off-by: Takashi Iwai <tiwai@suse.de>