staging: olpc_dcon: add config options for XO_1 and XO_1_5, drop hardcoded XO-1 stuff

This adds CONFIG_FB_OLPC_DCON_1 and CONFIG_FB_OLPC_DCON_1_5 options for
allowing selection of XO-1 and/or XO-1.5 DCON support.  In the process,
it also forces the xo_1.c and xo_1_5.c files to build as separate units,
correctly selects between XO-1 and XO-1.5 at runtime, and adds some
hacks to allow xo_1_5.c to build.

This isn't the cleanest patch, but it'll get better as more global
variables are dropped.

Signed-off-by: Andres Salomon <dilinger@queued.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/staging/olpc_dcon/olpc_dcon_xo_1.c b/drivers/staging/olpc_dcon/olpc_dcon_xo_1.c
index 043198d..be52b6c 100644
--- a/drivers/staging/olpc_dcon/olpc_dcon_xo_1.c
+++ b/drivers/staging/olpc_dcon/olpc_dcon_xo_1.c
@@ -195,7 +195,7 @@
 	return status;
 }
 
-static struct dcon_platform_data dcon_pdata_xo_1 = {
+struct dcon_platform_data dcon_pdata_xo_1 = {
 	.init = dcon_init_xo_1,
 	.bus_stabilize_wiggle = dcon_wiggle_xo_1,
 	.set_dconload = dcon_set_dconload_1,