Revert "backlight: scale max current when the brightness level is below 15 instead of using always 0."

This reverts commit 81c696041a331769066b2b66edaa9eeda4031a63.
Revert "backlight: add minimum backlight brightness module param."

This reverts commit c45e077edb1e8890094b959060db950406865243.
Revert "backlight: clean the code."

This reverts commit 97b0bbce04a79b7559eac1d39c0bf7ac541cf29c.
Revert "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."

This reverts commit 504d1f8dc2e97c4217cb06021da52aa79386ccdb.
Revert "Backlight dimmer mod: more gradual transitions"

This reverts commit b32c4195a6c8e0ab558a8d1656ce519e6daf9233.
Revert "More gradual levels for backlight dimmer mod (based on @mzhou module)"

This reverts commit 308af4dcb8431a96c8d979005a4af430fdc8ea9b.
Revert "Add backlight dimmer option"

This reverts commit ee1435503f39a090493f0166e36f465aa206257d.