hv:remove some unnecessary includes

--remove unnecessary includes
--remove unnecssary forward-declaration for 'struct vhm_request'

Tracked-On: #861
Signed-off-by: Mingqiang Chi <mingqiang.chi@intel.com>

hypervisor/boot/guest/vboot_info.c

@@ -10,7 +10,6 @@
 #include <per_cpu.h>
 #include <irq.h>
 #include <boot_context.h>
-#include <sprintf.h>
 #include <multiboot.h>
 #include <pgtable.h>
 #include <zeropage.h>