refactor(interrupts): add queued counter

Adding queued counter to help checking whether the VI
queue is full or not, and use the full buffer size.

Signed-off-by: J-Alves <joao.alves@arm.com>
Change-Id: I13f2d32d3633e617c714990741966eb7070f2ba7
diff --git a/inc/hf/vcpu.h b/inc/hf/vcpu.h
index bd92f81..7f7ebf1 100644
--- a/inc/hf/vcpu.h
+++ b/inc/hf/vcpu.h
@@ -81,6 +81,7 @@
 	uint32_t vint_buffer[VINT_QUEUE_MAX];
 	uint16_t head;
 	uint16_t tail;
+	size_t queued_vint_count;
 };
 
 struct interrupts {