ata: libahci_platform: Get rid of dup message when IRQ can't be retrieved

platform_get_irq() will print a message when it fails.
No need to repeat this.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>