Revert "LCD_KCAL: Prevent out-of-range input values"

This reverts commit c3cdc09800e6189bd67b032e49ec942df5f0eee2.
Revert "LCD_KCAL: Introduce configurable kcal_min"

This reverts commit 95584be340d93cc0d460894fc4a38fe464bbb46d.
Revert "lcd_kcal: Correct the copyright information"

This reverts commit d8df87b7b53455051788260d6064ccf618b2898b.