IRQCHIP: mips-gic: Fix typo in comment

Fix typo in comment in gic_get_c0_perfcount_int:
"erformance" -> "performance".

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andrew Bresticker <abrestic@chromium.org>
Patchwork: https://patchwork.linux-mips.org/patch/9126/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>