arm: sa1100: move irda header to linux/platform_data

In the end asm/mach/irda.h header is not used by anybody except sa1100.
Move the header to the platform data includes dir and rename it to
irda-sa11x0.h.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>