Increase the granularity of the brightness (currently there are 16 brightness levels)

[devnoname120]

Currently the brightness tables are replaced right into the SceOled / SceLcd modules. One limitation is that there are only 16 different levels of brightness (original restriction, not a vitabright issue).

This could be changed especially for LCD devices since the slider from the Vita UI has way more than 16 levels.

This would be complicated for OLED since their lookup table is not very well understood yet. But for LCD devices this should be doable because the command is just a number between 0 and 255 corresponding to the brightness.

Some hooking might be needed in the functions calling ksceLcdSetBrightness if they reduce the precision (if I recall correctly they reduce the precision on OLED).

Note that since I don't own a PS Vita 2000 (LCD screen), I don't have the motivation to do this. You're welcome to chime in and do a pull request!