MIPS: CFE: Add cfe_die()

Add a cfe_die() implementation which is useful when the kernel does an
early panic and no console is registered. This allows us to print
useful diagnostics such as an invalid DTB having been
configured/selected.

Since the BMIPS_GENERIC kernel can be built with support for multiple
processors, we need to do a runtime determination of the type of CPU
that we are executing on to perform the appropriate XKS01 disabling.

Since cfe_init() + cfe_die() could be conceivably called at very early
stages of the kernel boot, before cpu_probe(), we do not rely on the
structure(s) populated by cpu_probe().

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>