utgard: add some basic dt and platform stuff, similar to midgard
enable gpu on radxa rock
utgard: add a rk platform

This is most likely completely wrong and will likely produce crashes if one
tries to use it, but at least it gets the mali400mp to sucessfully probe.

[drm] Initialized drm 1.1.0 20060810
Mali<2>: Inserting Mali v600 device driver.
[...]
Mali<2>: Mali PP: Creating Mali PP core: Mali_PP0
Mali<2>: Mali PP: Base address of PP core: 0x10098000
Mali<2>: Found Mali GPU Mali-400 MP r1p1
Mali<2>: Mali L2 cache: Created Mali_L2: 128K, 4-way, 64byte cache line, 128bit external bus
Mali<2>: Mali MMU: Creating Mali MMU: Mali_GP_MMU
Mali<2>: Mali GP: Creating Mali GP core: Mali_GP
Mali<2>: Mali MMU: Creating Mali MMU: Mali_PP0_MMU
Mali<2>: Mali PP: Creating Mali PP core: Mali_PP0
Mali<2>: Mali PP: Base address of PP core: 0x10098000
Mali<2>: Mali MMU: Creating Mali MMU: Mali_PP1_MMU
Mali<2>: Mali PP: Creating Mali PP core: Mali_PP1
Mali<2>: Mali PP: Base address of PP core: 0x1009a000
Mali<2>: Mali MMU: Creating Mali MMU: Mali_PP2_MMU
Mali<2>: Mali PP: Creating Mali PP core: Mali_PP2
Mali<2>: Mali PP: Base address of PP core: 0x1009c000
Mali<2>: Mali MMU: Creating Mali MMU: Mali_PP3_MMU
Mali<2>: Mali PP: Creating Mali PP core: Mali_PP3
Mali<2>: Mali PP: Base address of PP core: 0x1009e000
Mali<2>: 4+0 PP cores initialized
Mali: Mali device driver loaded