mtd: ixp4xx: oops in ixp4xx_flash_probe

In commit "c7975330 mtd: abstract last MTD partition parser argument" the
third argument of "mtd_device_parse_register()" changed from start address
of the MTD device to a pointer to a struct.

The "ixp4xx_flash_probe()" function was not converted properly, causing
an oops during boot.

This patch fixes the problem by filling the needed information into a
"struct mtd_part_parser_data" and passing it to
"mtd_device_parse_register()".

Signed-off-by: Marc Kleine-Budde <mkl@blackshift.org>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: stable@kernel.org [3.2+]
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>