lightnvm: disable interleaved metadata

Currently pblk only check the size of I/O metadata and does not take
into account if this metadata is in a separate buffer or interleaved
in a single metadata buffer.

In reality only the first scenario is supported, where second mode will
break pblk functionality during any IO operation.

This patch prevents pblk to be instantiated in case device only
supports interleaved metadata.

Reviewed-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Igor Konopko <igor.j.konopko@intel.com>
Signed-off-by: Matias Bjørling <mb@lightnvm.io>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

include/linux/lightnvm.h

@@ -357,6 +357,7 @@ struct nvm_geo {
 	u32	clba;		/* sectors per chunk */
 	u16	csecs;		/* sector size */
 	u16	sos;		/* out-of-band area size */
+	bool	ext;		/* metadata in extended data buffer */
 
 	/* device write constrains */
 	u32	ws_min;		/* minimum write size */