hv: cleanup vmcs.h

-- move 'RFLAGS_AC' to cpu.h
-- move 'VMX_SUPPORT_UNRESTRICTED_GUEST' to msr.h
   and rename it to 'MSR_IA32_MISC_UNRESTRICTED_GUEST'
-- move 'get_vcpu_mode' to vcpu.h
-- remove deadcode 'vmx_eoi_exit()'

Tracked-On: #1842
Signed-off-by: Mingqiang Chi <mingqiang.chi@intel.com>
Reviewed-by: Jason Chen CJ <jason.cj.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

hypervisor/arch/x86/guest/guest_memory.c

@@ -6,6 +6,7 @@
 
 #include <types.h>
 #include <errno.h>
+#include <vmx.h>
 #include <guest_memory.h>
 #include <vcpu.h>
 #include <vm.h>

hypervisor/arch/x86/guest/vmsr.c

@@ -11,7 +11,6 @@
 #include <cpuid.h>
 #include <vcpu.h>
 #include <vm.h>
-#include <vmcs.h>
 #include <vmx.h>
 #include <sgx.h>
 #include <guest_pm.h>