USB fixes for donated Ampere system

[Hector Oron <zumbi@debian.org>]

Hello,

  Ampere donated some machines for the ARM ports, those machines need
some fixes for USB, I have built a test stable kernel with it and John
has validated it was working. Do you think we could land these fixes
in the buster
branch?

John has put it patches at: https://github.com/jvillal-amp/linux-4.19

I have submitted MR!270 to salsa looking for comments
  https://salsa.debian.org/kernel-team/linux/-/merge_requests/270

Backported patchset:

lib/genalloc: add gen_pool_dma_zalloc() for zeroed DMA allocations
https://github.com/torvalds/linux/commit/da83a722959a82733c3ca60030cc364ca2318c5a

USB: use genalloc for USB HCs with local memory
https://github.com/torvalds/linux/commit/b0310c2f09bbe8aebefb97ed67949a3a7092aca

USB: drop HCD_LOCAL_MEM flag
https://github.com/torvalds/linux/commit/2d7a3dc3e24f43504b1f25eae8195e600f4cce8

usb: don't create dma pools for HCDs with a localmem_pool
https://github.com/torvalds/linux/commit/dd3ecf17ba70a70d2c9ef9ba725281b84f8eef1

usb: add a hcd_uses_dma helper
https://github.com/torvalds/linux/commit/edfbcb321faf07ca970e4191abe061deeb7d378

Regards
-- 
 Héctor Orón  -.. . -... .. .- -.   -.. . ...- . .-.. --- .--. . .-.