MIPS: Update bmips_stb_defconfig

Align the bmips_stb_defconfig with its downstream version at:
https://github.com/Broadcom/stblinux-4.1/blob/master/linux/arch/mips/configs/bmips_stb_defconfig
to be slightly more useful and include support for all of these options:

- latest Broadcom STB drivers
- support for high resolution timers
- cpufreq
- function tracers
- extending command line from DTB
- task lockup detector
- strong stack protector support
- IP auto-configuration

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>