ARM: 5875/1: ep93xx: use pr_fmt in clock.c

Use pr_fmt to prefix kernel output with the module name and change
all printk messages to pr_<level> format.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Ryan Mallon <ryan@bluewatersys.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>