media: hantro: Fix JPEG encoder ENUM_FRMSIZE on RK3399

Since 79c987de, enumerating framesize on format set with "MODE_NONE"
(any raw formats) is reporting an invalid frmsize.

  Size: Stepwise 0x0 - 0x0 with step 0/0

Before this change, the driver would return EINVAL, which is also invalid
but worked in GStreamer. The original intent was not to implement it, hence
the -ENOTTY return in this change. While drivers should implement
ENUM_FRMSIZE for all formats and queues, this change is limited in scope to
fix the regression.

This fixes taking picture in Gnome Cheese software, or any software using
GSteamer to encode JPEG with hardware acceleration.

Fixes: 79c987de ("media: hantro: Use post processor scaling capacities")
Reported-by: Robert Mader <robert.mader@collabora.com>
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Reviewed-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
Reviewed-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Tested-by: Robert Mader <robert.mader@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/media/platform/verisilicon/hantro_v4l2.c

@@ -161,8 +161,11 @@ static int vidioc_enum_framesizes(struct file *file, void *priv,
 	}
 
 	/* For non-coded formats check if postprocessing scaling is possible */
-	if (fmt->codec_mode == HANTRO_MODE_NONE && hantro_needs_postproc(ctx, fmt)) {
+	if (fmt->codec_mode == HANTRO_MODE_NONE) {
+		if (hantro_needs_postproc(ctx, fmt))
 			return hanto_postproc_enum_framesizes(ctx, fsize);
+		else
+			return -ENOTTY;
 	} else if (fsize->index != 0) {
 		vpu_debug(0, "invalid frame size index (expected 0, got %d)\n",
 			  fsize->index);