Merge tag 'at91-cleanup4' into arm-soc-for-next+at91-3.20-cleanup

Fourth cleanup/soc batch for 3.20:
- merge all the at91sam9 code and remove the empty SoC-specific files
- remove the at91_boot_soc that is now useless in a DT context
- move the sram code in PM code as it's now only used there
- some file + function name changes after this big cleanup

Conflicts:
	arch/arm/mach-at91/board-dt-sama5.c