ffmpeg: update v4l2-request patch

Patch created using revisions 293e067..0b8eff4
from branch v4l2-request-hwaccel-4.4.1-Nexus-Alpha1 of https://github.com/jernejsk/FFmpeg

and ffmpeg (Rockchip): drop max slices patch

projects/Rockchip/patches/ffmpeg/ffmpeg-0004-v4l2request-hevc-increase-max-slices.patch

@@ -1,25 +0,0 @@
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Alex Bee <knaerzche@gmail.com>
-Date: Sun, 20 Jun 2021 20:19:19 +0200
-Subject: [PATCH] v4l2request: hevc: increase max slices
-
-It's required by some HEVC confromance tests
-
-Signed-off-by: Alex Bee <knaerzche@gmail.com>
----
- libavcodec/v4l2_request_hevc.c | 2 +-
- 1 file changed, 1 insertion(+), 1 deletion(-)
-
-diff --git a/libavcodec/v4l2_request_hevc.c b/libavcodec/v4l2_request_hevc.c
-index be78382444..35ec87e310 100644
---- a/libavcodec/v4l2_request_hevc.c
-+++ b/libavcodec/v4l2_request_hevc.c
-@@ -21,7 +21,7 @@
- #include "v4l2_request.h"
- #include "hevc-ctrls.h"
- 
--#define MAX_SLICES 16
-+#define MAX_SLICES 32
- 
- typedef struct V4L2RequestControlsHEVC {
-     struct v4l2_ctrl_hevc_sps sps;