hv:Replace vuart pointer with instance in structure vm

-- update 'vuart' field in 'struct vm' from pointer
   to instance
-- replace MACRO with inline function for vm_vuart,
   and move it to vm.h
-- change vuart_init to void type
-- rename struct vuart -->struct acrn_vuart

Signed-off-by: Mingqiang Chi <mingqiang.chi@intel.com>
Reviewed-by: Anthony Xu <anthony.xu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

hypervisor/debug/console.c

@@ -34,7 +34,7 @@ char console_getc(void)
 
 static void console_timer_callback(__unused void *data)
 {
-	struct vuart *vu;
+	struct acrn_vuart *vu;
 
 	/* Kick HV-Shell and Uart-Console tasks */
 	vu = vuart_console_active();