MIPS: reduce print level for cache information

Default printk log level is KERN_WARNING. This makes automatic log
parsing problematic, since we get false positive alarms on not critical
information.

Set all not critical cache related information to KERN_INFO, the same level
as used on most kernel drivers.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>