ARM: PXA: fix lubbock PCMCIA driver build error

Fix:

ERROR: "pxa2xx_configure_sockets" [drivers/pcmcia/pxa2xx_lubbock_cs.ko] undefined!

by exporting the required function.
Acked-by: NEric Miao <eric.y.miao@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

drivers/pcmcia/pxa2xx_base.c

@@ -231,6 +231,7 @@ void pxa2xx_configure_sockets(struct device *dev)
 
 	__raw_writel(mecr, MECR);
 }
+EXPORT_SYMBOL(pxa2xx_configure_sockets);
 
 static const char *skt_names[] = {
 	"PCMCIA socket 0",