arm: versatile : Fix typo introduced in irq namespace cleanup

Commit 6845664a(arm: Cleanup the irq namespace) introduces a typo
causing a build failure for the versatile platform.

[ tglx: Sorry, my bad. Have no idea how I fatfingered that ]

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
LKML-Reference: <20110330060229.27397.7628.stgit@ponder>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>