refactor: rename implicit_completion_signal

Rename "implicit_completion_signal" to
"requires_deactivate_call".

Signed-off-by: J-Alves <joao.alves@arm.com>
Change-Id: I298bf74a9cf8dd64f68109eb8c4b8848407eb536
diff --git a/src/vcpu.c b/src/vcpu.c
index b5f0d2f..ec7f54f 100644
--- a/src/vcpu.c
+++ b/src/vcpu.c
@@ -517,5 +517,5 @@
 
 	vcpu = vcpu_locked.vcpu;
 	vcpu->preempted_vcpu = NULL;
-	vcpu->implicit_completion_signal = false;
+	vcpu->requires_deactivate_call = false;
 }