Merge tag 'at91-cleanup' into at91-4.1-multiplatform

First batch of cleanup for 4.1:
- little phy fixup that is not needed anymore
- hudge cleanup of the PM code:
  - removal of "use slow clock" option => always use this for suspend to RAM
  - quicker suspend as the asm function is copied only once to SRAM
  - use of the same asm function for "standby" and "mem" types of suspend
    actions
  - adaptation to the ARMv7 processors