pcmcia: introduce autoconfiguration feature

Introduce an autoconfiguration feature to set certain values in
pcmcia_loop_config(), instead of copying the same code over and over
in each PCMCIA driver. At first, introduce the following options:

CONF_AUTO_CHECK_VCC	check or matching Vcc entry
CONF_AUTO_SET_VPP	set Vpp
CONF_AUTO_AUDIO		enable the speaker line

CC: netdev@vger.kernel.org
CC: linux-wireless@vger.kernel.org
CC: linux-ide@vger.kernel.org
CC: linux-usb@vger.kernel.org
CC: laforge@gnumonks.org
CC: linux-mtd@lists.infradead.org
CC: alsa-devel@alsa-project.org
CC: linux-serial@vger.kernel.org
CC: Jiri Kosina <jkosina@suse.cz>
CC: linux-scsi@vger.kernel.org
Acked-by: Gustavo F. Padovan <padovan@profusion.mobi> (for drivers/bluetooth)
Tested-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>