From Vita Development Wiki
// scale must be between 0.80000001 and 1.20000005
// scaling arg has yet to be studied. scaling
seams to be coded on 6 bits. Maybe it is a bitfield config.
// scaling seen values: 1, 0x40, 0x80
int sceDisplaySetScaleConfForDriver(float scale, SceDisplayHead head, SceDisplayFrameBufType fb_idx, int scaling);