MIPS: BMIPS: Add support for Broadcom BCM97435SVMB
Add a DTS file and Kconfig entry for the BCM97435SVMB evaluation board
using bcm7435.dtsi as an example.
The current code needs some tweaking to allow us to use the
dual-threaded dual BMIPS5200 CPUs, so for now we limit ourselves to
allowing just a single CPU to be booted.