ata: sata_mv: Fixes expected number of resources now IRQs are gone

The commit a1a2b712 ("of/platform: Drop static setup of IRQ
resource from DT core") stopped IRQ resources being available as
platform resources. This broke the sanity check for the expected
number of resources in the Marvell SATA driver which expected two
resources, the IO memory and the interrupt.

Change the sanity check to only expect the IO memory.

Cc: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Fixes: a1a2b712 ("of/platform: Drop static setup of IRQ resource from DT core")
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>