cs5535-clockevt: typo, it's MFGPT, not MFPGT

Signed-off-by: Jens Rottmann <JRottmann@LiPPERTEmbedded.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>