power: Add CONFIG_SPL_POWER_DOMAIN config

Add CONFIG_SPL_POWER_DOMAIN config entry.
Build drivers/power/domain if this config is selected.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Cc: Simon Glass <sjg@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
3 files changed