[ARM] TS-78xxx NAND resource type should be IORESOURCE_MEM

The type was IORESOURCE_IO which is not what is expected by
plat_nand_probe(). This device has not worked since 2d098a72
("mtd: plat_nand: request memory resource before doing ioremap").

Signed-off-by: Michael Spang <mspang@csclub.uwaterloo.ca>
Signed-off-by: Nicolas Pitre <nico@fluxnic.net>