staging: ath6kl: remove-typedef AR6K_IRQ_ENABLE_REGISTERS

remove-typedef -s AR6K_IRQ_ENABLE_REGISTERS \
	"struct ar6k_irq_enable_registers" drivers/staging/ath6kl/

Cc: Naveen Singh <naveen.singh@atheros.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>