822a3c22dc
The env variable "SN" is used to store the serial number on DH electronics
SoMs. New SoMs will use the variable "dh_som_serial_number". To ensure
compatibility, these env variables are synchronized. This is achieved
using callback functions.
Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
Reviewed-by: Marek Vasut <marex@denx.de>
(cherry picked from commit 1c9fe756ed)