pata_platform: Remove useless irq_flags field

IRQ flags can be obtained from resource structure, there are no need
to use additional field in the platform_data to store these values.
This patch removes this field and convert existing users of this driver
to use IRQ flags from the resources.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Tejun Heo <tj@kernel.org>