update drm to linux 5.15.14

new hardware support includes

Intel
ehl/Elkhart Lake (embedded)
jsl/Jasper Lake (atom)
rkl/Rocket Lake (desktop)

AMD
van gogh APU (gfx1033)
yellow carp / rembrandt APU (gfx1035?)
Ryzen 6000 APU
navy flounder / navi 22 (gfx1031)
RX 6700, RX 6700 XT, RX 6700M, RX 6800M, RX 6850M XT
dimgrey cavefish / navi 23 (gfx1032)
Pro W6600, Pro W6600M, RX 6600, RX 6600 XT, RX 6600M,
RX 6600S, RX 6650M, RX 6650M XT, RX 6700S, RX 6800S
beige goby / navi 24 (gfx1034)
RX 6500 XT, RX 6400, RX 6500M, RX 6300M

Thanks to the OpenBSD Foundation for sponsoring this work
niklas@ for helping with ttm and amdgpu and patrick@ for adapting
rockchip drm.