Merge tag 'arc-fixes-for-2020.01-rc2' of https://gitlab.denx.de/u-boot/custodians/u-boot-arc

ARC fixes for v2020.01-rc2

The main change is move to DM_MMC of yet 2 another ARC boards:
AXS101 & IoTDK.

Among that we improve handling of stock-formatted SD-cards of high volume
on EM SDP as well as introduction of reset driver for HSDK which is required
for prepser reinitialization of some peripherals like USB etc.