With everything in place (i.e. the new efuse driver, the clk-support
for the non-secure efuse block, and the board-specific functions to
derive 'serial#' from the cpu-id within the efuses), enable this in
the RK3399-Q7 defconfig.
Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com> Acked-by: Simon Glass <sjg@chromium.org>