The bulk of it is (finally!) some DT sync from the kernel. We refrained
from syncing one incompatible change, as this would spoil booting Linux
kernels before v5.13 with U-Boot's DT (via UEFI, for instance).
I test booted Linux v5.18 and v5.4 with that new DT on some boards, and
the headless peripherals (MMC, USB, Ethernet) seemed to work.
The rest are fixes:
- silencing missing clock warnings due to the new pinctrl driver
- fixing "UART0 on PortF", allowing UART access through the SD card pins
- add an F1C100s clock driver, to enable MMC support (SPI comes later)
- some cleanups for CONS_INDEX_n in Kconfig

Tested on BananaPi-M1, Pine64-LTS, Pine-H64, X96-Mate (H616) and
OrangePi-Zero.