CHROMIUM: [media] rk3288-vpu: vp8e: increase frame hdr size

CHROMIUM: [media] rk3288-vpu: vp8e: 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.

This needs change the define in v4lplugin too.
(change id: Ia6c2271b727218692c4e0b1603d243f32d2f1d77)

BUG=chromium:497324
TEST=screen share through Hangouts

Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Reviewed-on: https://chromium-review.googlesource.com/277398
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Change-Id: I06e7712420404c43661774e176a7b9333ddc3def
Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Signed-off-by: Yakir Yang <ykk@rock-chips.com>