Allow DT to define the voltage domain name (new string property voltd-name) instead of the voltage domain ID from property reg. This change makes SCMI regulators binding more flexible between SCMI server and U-Boot SCMI agent. Change-Id: I8e1cbd0745bf61d00238eb1d13ff73ff99920b38 Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org> Reviewed-on: https://gerrit.st.com/c/mpu/oe/st/u-boot/+/194453