configs: stm32: Enable CONFIG_DM_REGULATOR for stm32f769-disco
Since commit
5bc6f8c2a97e("video: stm32: remove test on CONFIG_DM_REGULATOR")
backlight was broken with the following message at boot:
stm32-display-dsi dsi@
40016c00: Warning: cannot get phy dsi supply
stm32_display display-controller@
40016800: panel panel enable backlight error -38
DM_REGULATOR flag must be enabled to fix this issue
Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>