MIPS: Netlogic: Merge platform usb.h to usb-init.c

The definitions are not used anywhere else, and merging it will
make adding the new USB definitions for XLPII series easier.
While there, cleanup some whitespace in usb-init.c. There is no
change to logic due to this commit.

Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/5027/
Acked-by: John Crispin <blogic@openwrt.org>