I don't know what software you are using, but in SDK 6.0 you can add your display and it should look something like:
File "da8xx-fb.c":
[number] = {
.name = "DISPLAY_NAME",
.width = 800,
.height = 480,
.hfp = 40,
.hbp = 88,
.hsw = 128,
.vfp = 11,
.vbp = 32,
.vsw = 2,
.pxl_clk = 33200000,
.invert_pxl_clk = 0,
},