OMAPDSS: DISPC: Fix FIR coefficients

coef3_M8 had an incorrect phase with 50% more intensity. This resulted in
banding on slightly down/upscaled images. Fixed a rounding error in coef5_M9.

Also removed ARRAY_LEN macro as ARRAY_SIZE is the standard linux one.

Signed-off-by: Lajos Molnar <lajos@ti.com>
Signed-off-by: Archit Taneja <archit@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>