hv: fixup relocation delta for symbols belong to entry section

This is to enable relocation for code32.

- RIP relative addressing is available in x86-64 only so we manually add
  relocation delta to the target symbols to fixup code32.

- both code32 and code64 need to load GDT hence both need to fixup GDT
  pointer. This patch declares separate GDT pointer cpu_primary64_gdt_ptr
  for code64 to avoid double fixup.

- manually fixup cpu_primary64_gdt_ptr in code64, but not rely on relocate()
  to do that. Otherwise it's very confusing that symbols from same file could
  be fixed up externally by relocate() or self-relocated.

- to make it clear, define a new symbol ld_entry_end representing the end of
  the boot code that needs manually fixup, and use this symbol in relocate()
  to filter out all symbols belong to the entry sections.

Tracked-On: #4441
Reviewed-by: Fengwei Yin <fengwei.yin@intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>

hypervisor/include/arch/x86/boot/ld_sym.h

@@ -10,6 +10,7 @@
 extern uint8_t		ld_text_end;
 extern uint8_t		ld_bss_start;
 extern uint8_t		ld_bss_end;
+extern uint8_t		ld_entry_end;
 extern const uint8_t	ld_trampoline_load;
 extern uint8_t		ld_trampoline_start;
 extern uint8_t		ld_trampoline_end;