Merge tag 'at91-cleanup2' into at91-next

Second batch of cleanup for 4.1:
- remove unused matrix header files
- dbgu + chip identification: new driver for SoC detection
  this allow to remove all additional io mapping
- remove old non-standard AT91 setup code

diff --cc arch/arm/boot/dts/at91sam9n12.dtsi
Simple merge

diff --cc arch/arm/boot/dts/sama5d4.dtsi
Simple merge