refactor(interrupts): make bitmap and count functions private

Move the functions to modify the interrupt bitmap or count into
vcpu.c and make them static so only the getter functions can be
accessed externally. This helps ensure consistency between the
bitmap, queue and count.

Also rename the count_get functions to match the
vcpu_virt_interrupt_ naming used for other public functions
for virtual interrupts within the vcpu.c file.

Signed-off-by: Daniel Boulby <daniel.boulby@arm.com>
Change-Id: Id4eaa76f448ddddfd9ca99e2e12789b0c57c20f3
diff --git a/src/ffa/hypervisor/indirect_messaging.c b/src/ffa/hypervisor/indirect_messaging.c
index 0c29348..3e43349 100644
--- a/src/ffa/hypervisor/indirect_messaging.c
+++ b/src/ffa/hypervisor/indirect_messaging.c
@@ -70,7 +70,7 @@
 	 * Don't block if there are enabled and pending interrupts, to match
 	 * behaviour of wait_for_interrupt.
 	 */
-	interrupted = (vcpu_interrupt_count_get(current_locked) > 0);
+	interrupted = (vcpu_virt_interrupt_count_get(current_locked) > 0);
 
 	return interrupted;
 }