scripts: west: commands: completion: add twister --log-level completion

Add bash tab-completion for for the newly introduced "west twister
--log-level" arguments.

Signed-off-by: Henrik Brix Andersen <hebad@vestas.com>

scripts/west_commands/completion/west-completion.bash

@@ -1064,6 +1064,7 @@ __comp_west_twister()
 		--coverage-tool
 		--exclude-platform -P
 		--filter
+                --log-level
 		--platform -p
 		--runtime-artifact-cleanup -M
 	"
@@ -1114,6 +1115,11 @@ __comp_west_twister()
 			return
 		        ;;
 
+		--log-level)
+		        __set_comp "CRITICAL DEBUG ERROR INFO NOTSET WARNING"
+			return
+		        ;;
+
 		--runtime-artifact-cleanup|-M)
 		        __set_comp "all pass"
 			return