[PATCH] OMAP: don't trace functions called from sched_clock

Rabin Vincent [off-list ref] writes:

omap_readl() is used from the sched_clock() implementations and so must
be marked notrace to avoid recursion in ftrace.  Same thing with
mpu_read() for OMAP1.

Signed-off-by: Rabin Vincent <redacted>

Acked-by: Kevin Hilman <redacted>