Revert "libv4l-rockchip_v2: Don't produce IDR frames periodically"

This reverts f3a47f0 because one GTS test starts failing from
the commit due to an unexpected bitrate of a produced bitstream.

BUG=b:187483451, b:190582833
TEST=com.google.android.media.gts.RtcVideoCodecTest#testSimulcastBitrateSyncH264

Change-Id: I24b8e08ad99c339f6936380acdff5556fbff49a2
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/libv4lplugins/+/2955426
Tested-by: Hirokazu Honda <hiroh@chromium.org>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Commit-Queue: Hirokazu Honda <hiroh@chromium.org>