vcap/v4l2: remove CentOS 7 compat

CentOS 7 is no longer supported by us - RHEL 8 or derivative (AlmaLinux)
is now required at least.

Author: MartinPulec

configure.ac

@@ -151,7 +151,6 @@ else
 fi
 
 if test $system = Linux; then
-        AC_CHECK_HEADERS([linux/version.h])
 	LDFLAGS="$LDFLAGS -Wl,--dynamic-list-data"
         COMMON_FLAGS="${COMMON_FLAGS:+$COMMON_FLAGS }-D_GNU_SOURCE"
 fi

src/video_capture/v4l2.c

@@ -44,11 +44,6 @@
 #ifdef HAVE_LIBV4LCONVERT
 #include <libv4lconvert.h>
 #endif
-#ifdef HAVE_LINUX_VERSION_H
-#include <linux/version.h>
-#else
-#define KERNEL_VERSION(x,y,z) -1
-#endif
 
 #include <assert.h>
 #include <errno.h>
@@ -690,11 +685,7 @@ static int vidcap_v4l2_init(const struct vidcap_params *params, void **state)
         memcpy(&s->src_fmt, &fmt, sizeof(fmt));
         memcpy(&s->dst_fmt, &fmt, sizeof(fmt));
         s->dst_fmt.fmt.pix.bytesperline = 0;
-#if LINUX_VERSION_CODE > KERNEL_VERSION(3,10,0)
         s->dst_fmt.fmt.pix.colorspace = V4L2_COLORSPACE_DEFAULT;
-#else // CentOS 7
-        s->dst_fmt.fmt.pix.colorspace = V4L2_COLORSPACE_REC709;
-#endif
 
         if(ioctl(s->fd, VIDIOC_G_PARM, &stream_params) != 0) {
                 log_perror(LOG_LEVEL_ERROR, MOD_NAME "Unable to get stream params");