Current timer routines (arch/mips/lib/timer.c) are implemented assuming
that MIPS32 coprocessor (CP0) resources, Counter and Compare registers
in this case, are available.  But this doesn't always work.

We need to make sure that all MIPS-based systems don't necessarily use
CP0 counter/compare registers as time keeping resources.  And some MIPS
variant processors might come with different hardware specs with genuine
MIPS32 CP0 registers.

With this change, each $(CPU)/ directory can have its own timer code.

Signed-off-by: Shinya Kuribayashi <skuribay@pobox.com>

Also move lib_$ARCH/config.mk to arch/$ARCH/config.mk

This change is intended to clean up the top-level directory structure
and more closely mimic Linux's directory organization.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>