vlr: optionally send IMEI early to HLR

When 'check-imei-rqd 1 early' is set in the config, send the IMEI to
the HLR before doing the location update with the HLR.

The OsmoHLR documentation referenced in the code will be added in
osmo-hlr.git's Change-Id I2dd4a56f7b8be8b5d0e6fc32e04459e5e278d0a9.

Related: OS#2542
Change-Id: I88283cad23793b475445d814ff49db534cb41244
diff --git a/src/libvlr/vlr_lu_fsm.h b/src/libvlr/vlr_lu_fsm.h
index 5cf13c7..b5c4a5e 100644
--- a/src/libvlr/vlr_lu_fsm.h
+++ b/src/libvlr/vlr_lu_fsm.h
@@ -9,6 +9,7 @@
 	VLR_ULA_S_WAIT_AUTH,	/* Waiting for Authentication */
 	VLR_ULA_S_WAIT_CIPH,	/* Waiting for Ciphering Complete */
 	VLR_ULA_S_WAIT_IMSI,	/* Waiting for IMSI from MS */
+	VLR_ULA_S_WAIT_HLR_CHECK_IMEI_EARLY, /* Waiting for Check IMEI result from HLR */
 	VLR_ULA_S_WAIT_HLR_UPD,	/* Waiting for end of HLR update */
 	VLR_ULA_S_WAIT_LU_COMPL,/* Waiting for LU complete */
 	VLR_ULA_S_WAIT_LU_COMPL_STANDALONE, /* Standalone VLR */