[IrDA]: Fix the AU1000 FIR dependencies

AU1000 FIR is broken, it should depend on SOC_AU1000.

Spotted by Jean-Luc Leger.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Samuel Ortiz <samuel@sortiz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>