Support Marvell bootloaders remapping registers at different locations

On Marvell platforms, the base address of the "internal registers" (i.e registers of all peripherals) can be configured at runtime. At reset, it is set to 0xD0000000, but it can freely be changed to some other location.

On all previous Marvell SoC families, Linux assumes the bootloader has remapped the internal registers at 0xF1000000, and Marvell is now moving to do the same on Armada 370/XP, since it allows to use as much RAM as possible in the 0 -> 4G area. However, due to early issues, until now, Marvell bootloaders were leaving the internal registers address set to 0xD0000000, and recently, Marvell has started shipping bootloaders that remapped those registers to 0xF1000000.

In order to support those two cases, we want to make sure the Device Tree is the only location where the physical base address of the internal registers is stored. This patch set removes the places where the physical base address of the registers was hardcoded and provides two Kconfig options for the earlyprintk UART address selection (one for 0xD0000000 and one for 0xF1000000).

It no longer uses the CP15 trick, nor it tries to do runtime remapping to 0xF1 if it wasn't done by the bootloader. But it allows to easily boot a kernel with both old and new bootloaders by doing a simple change, in a single location in the Device Tree.

This patch series is based on jcooper/mvebu/fixes-non-critical and jcooper/mvebu/cleanup, which contains 3 patches that are necessary to make this patch series work properly.