MIPS: Netlogic: merge of.c into setup.c

Move the function device_tree_init() from netlogic/xlp/of.c
to setup.c, and remove the wrapper functions reserve_mem_mach()
and free_mem_mach().

Remove file netlogic/xlp/of.c, and the Makefile entry for it.

Signed-off-by: Jayachandran C <jayachandranc@netlogicmicro.com>
Patchwork: http://patchwork.linux-mips.org/patch/4097/
Signed-off-by: John Crispin <blogic@openwrt.org>