Rockchip: increase frame hdr size

Currently, FRAME_HEADER_SIZE is 256, but i've saw
the hdr be larger then 256 when doing screen share.
so we should increase it.
Confirm with herman, the max would be 1188 + 2*19.

This needs change the define in kernel driver too.
(change id: I06e7712420404c43661774e176a7b9333ddc3def)

BUG=chromium:497324
TEST=screen share through Hangouts

Change-Id: Ia6c2271b727218692c4e0b1603d243f32d2f1d77
Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Reviewed-on: https://chromium-review.googlesource.com/277733


Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Trybot-Ready: Douglas Anderson <dianders@chromium.org>

libv4l-rockchip/libvpu/vp8_enc/encasiccontroller.h

@@ -238,7 +238,7 @@ typedef struct
   int32_t lfModeDelta[4];
 } regValues_s;
 
-#define FRAME_HEADER_SIZE 256
+#define FRAME_HEADER_SIZE 1280
 typedef struct
 {
   regValues_s regs;