samples: video: tcpserversink: fix build failure

The nxp,imx-csi node was removed from dts in a previous commit
which caused a build failure / regression in CI.

Use DEVICE_DT_GET_ANY() instead of DEVICE_DT_GET_ONE(), since
the latter requires a DT node present, while the former does
not and returns NULL if no such compat exists.

Signed-off-by: Chris Friedt <cfriedt@tenstorrent.com>