HV: cleanup CONFIG_COM_IRQ related code

move CONFIG_COM_IRQ code into vuart, because it is just
used for vuart.

Tracked-On: #2170
Signed-off-by: Minggui Cao <minggui.cao@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

hypervisor/debug/vuart.c

@@ -408,3 +408,8 @@ void vuart_init(struct acrn_vm *vm)
 	vuart_lock_init(vu);
 	vuart_register_io_handler(vm);
 }
+
+bool hv_used_dbg_intx(uint8_t intx_pin)
+{
+	return is_dbg_uart_enabled() && (intx_pin == CONFIG_COM_IRQ);
+}