HV: fix wrong gpa start of hpa2 in ve820.c

The current logic puts hpa2 above GPA 4G always, which is incorrect. Need
to set gpa start of hpa2 right after hpa1 when hpa1 size is less then 2G;

Tracked-On: #4458

Signed-off-by: Victor Sun <victor.sun@intel.com>

Author: jsun26intel

hypervisor/arch/x86/guest/ve820.c

@@ -190,6 +190,8 @@ void create_prelaunched_vm_e820(struct acrn_vm *vm)
 	} else {
 		/* need to revise length of hpa1 entry to its actual size */
 		vm->e820_entries[ENTRY_HPA1].length = vm_config->memory.size - MEM_1M;
+		/* need to set gpa_start for hpa2 */
+		gpa_start = vm->e820_entries[ENTRY_HPA1].baseaddr + vm->e820_entries[ENTRY_HPA1].length;
 		if ((vm_config->memory.size < MEM_2G)
 				&& (remaining_hpa2_size > (MEM_2G - vm_config->memory.size))) {
 			/* need to split hpa2 and add an entry for hpa2_lo */