ARM: sa1100: remove irda references

IRDA support is long gone, so there is no need to declare the
platform device data.

See-also: d64c2a76 ("staging: irda: remove the irda network stack and drivers")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

fixup sa1100 irda

Signed-off-by: Arnd Bergmann <arnd@arndb.de>