zephyr-coap-client: Add recipe for CoAP client

This sample application provides an example coap-client using the the MBEDTLS library.

Signed-off-by: Amit Kucheria <amit.kucheria.ext@huawei.com>
Signed-off-by: Naveen Saini <naveen.kumar.saini@intel.com>

recipes-kernel/zephyr-kernel/zephyr-coap-client.bb

+include zephyr-sample.inc
+
+ZEPHYR_SRC_DIR = "${S}/samples/net/sockets/coap_client"
+
+ZEPHYR_MODULES_append = "\;${S}/modules/lib/mbedtls"