Mali450 support

Created by: mmind

As one of the commits states, Mali450 does have some more blocks (load balancer, dma, broadcast and separate l2 caches), but seems to work somewhat nicely with only the basics like the L2 set up.

This can of course be expanded to support the additional features later on, but with this basic support I can at least run the "kmscube -d" demo on both Mali400 (rk3188-radxarock) as well as on my rk3328-rock64 board [the one from Pine64] using a Mali450MP2.

On the kernel-side I also end up with: [ 15.829968] lima ff300000.gpu: bus rate = 163840000 [ 15.830424] lima ff300000.gpu: mod rate = 163840000 [ 15.831940] lima ff300000.gpu: found 2 PPs [ 15.832351] lima ff300000.gpu: fail to get irq pmu [ 15.832801] lima ff300000.gpu: no PMU present [ 15.833459] lima ff300000.gpu: l2 cache 8K, 4-way, 64byte cache line, 128bit external bus [ 15.834344] lima ff300000.gpu: gp - mali450 version major 0 minor 0 [ 15.838300] lima ff300000.gpu: l2 cache 64K, 4-way, 64byte cache line, 128bit external bus [ 15.839317] lima ff300000.gpu: pp0 - mali450 version major 0 minor 0 [ 15.840096] lima ff300000.gpu: pp1 - mali450 version major 0 minor 0 [ 15.841510] [drm] Initialized lima 1.0.0 20170325 for ff300000.gpu on minor 0