ARM: perf: use pr_* instead of printk

There are a few remaining uses of printk in the ARM perf code, so move
them over to the pr_* variants instead.

Reported-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --cc arch/arm/kernel/perf_event_cpu.c
Simple merge

diff --cc arch/arm/kernel/perf_event_v7.c
Simple merge