hv: fixup addresses in the c code for relocation

- Trampoline code doesn't have the same relocation delta with HV,
  Need to manually patch them when referenced from HV
- replace all references to CONFIG_RAM_START with the actual HV load
  address

Signed-off-by: Zheng Gen <gen.zheng@intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>

hypervisor/boot/reloc.c

@@ -131,3 +131,19 @@ void _relocate(void)
 		start = (struct Elf64_Rel *)((char *)start + size);
 	}
 }
+
+uint64_t read_trampoline_sym(void *sym)
+{
+	uint64_t *hva;
+
+	hva = HPA2HVA(trampoline_start16_paddr) + trampoline_relo_addr(sym);
+	return *hva;
+}
+
+void write_trampoline_sym(void *sym, uint64_t val)
+{
+	uint64_t *hva;
+
+	hva = HPA2HVA(trampoline_start16_paddr) + trampoline_relo_addr(sym);
+	*hva = val;
+}