drivers: video: esp32_dvp: add missing capability property

In the ESP32 video driver, set the caps.min_vbuf_count field to
indicate that a single buffer is enough. Fix use of un-initialized
memory breaking the samples in some situations.

Signed-off-by: Josuah Demangeon <me@josuah.net>

Author: josuah

drivers/video/video_esp32_dvp.c

@@ -245,6 +245,9 @@ static int video_esp32_get_caps(const struct device *dev, struct video_caps *cap
 {
 	const struct video_esp32_config *config = dev->config;
 
+	/* A single buffer is enough to perform a transfer */
+	caps->min_vbuf_count = 1;
+
 	/* ESP32 produces full frames */
 	caps->min_line_count = caps->max_line_count = LINE_COUNT_HEIGHT;