wifi: airo: remove ISA_DMA_API dependency

This driver does not actually use the ISA DMA API, it is purely
PIO based, so remove the dependency.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230417205131.1560074-1-arnd@kernel.org