MIPS: Netlogic: Platform changes for XLS USB

Add USB initialization code, setup resources and add USB platform
driver in mips/netlogic/xlr/platform.c.
Add USB support for XLR/XLS platform in Kconfig.

Signed-off-by: Jayachandran C <jayachandranc@netlogicmicro.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3759/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>