MIPS: Netlogic: Split reset code out of smpboot.S

The reset and core initialization code should be available for
uniprocessor as well. This changes is just to take out the code
into a different file, without any change to the logic.

The change for  uniprocessor initialization code is in a later patch.

Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5423/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>