Create new Channel ID/ro.carrier retkr for South Korea.

Changes:
channelID: 214 (decimal)
ro.carrier: retkr

Change-Id: I957f22b6f46b346924679dca1b3015301bfbedfe
Signed-off-by: zhengyd2 <zhengyd2@motorola.com>
Reviewed-on: https://gerrit.mot.com/1969918
SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Tested-by: Jira Key
Reviewed-by: Tarciano Facco Pegoraro <tarciano@motorola.com>
Reviewed-by: Tao Sun <suntao2@motorola.com>
Submit-Approved: Jira Key

qcom/carrier-channel-ids.dtsi

@@ -228,7 +228,7 @@
 		"retjp",	/* 211 */
 		"softbank",	/* 212 */
 		"optus",	/* 213 */
-		"undefined",	/* 214 */
+		"retkr",	/* 214 */
 		"undefined",	/* 215 */
 		"undefined",	/* 216 */
 		"undefined",	/* 217 */