Revert "dts: lm3630: lower min brightness to 1"

This reverts commit 0d51d0b5e6f6c49959c77e917e393c25dccb890a.
Revert "dts: lm3630: lower blmap for lower brightness levels"

This reverts commit e3ae716988c4c15ed04525b7a56d58337e1cb757.
drivers: video: Add backlight dimmer option

This is based on n5dim by @mzhou  https://github.com/mzhou/n5dim

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
drivers: video: gradual transitions for backlight dimmer

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
video: backlight: enable backlight_dimmer by default. Auto-brightness looks great with this.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
ARM/dt: hammerhead: Reduce minimum panel brightness

Default minimum brightness is a tad too high, this change makes reading
in a dark environment much more enjoyable. A value of 3 is still within
the valid range (see lm3630 blmap).

Change-Id: I40f690e7a06459a06db939c37108bae6fc9c52d6
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
backlight: fix a bug where the screen would be completely dark or near darkness with backlight_dimmer enabled when the display dimmed. The brightness level can't be any lower than dev->min_brightness and previous code allowed that to happen, so fix it.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
backlight: clean the code.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>