arm: dts: iot2050: Add cfg register space for ringacc and udmap

Recent unrelated fixes (9876ae7d) revealed that we were missing bits
from 2af181b5 in the IOT2050 dt. Add them, but only for main U-Boot.
SPL loads from QSPI only, thus cannot use DMA.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>