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/boot/include/reloc.h

@@ -13,7 +13,4 @@ extern uint64_t get_hv_image_base(void);
 /* external symbols that are helpful for relocation */
 extern uint8_t		_DYNAMIC[1];
 
-extern uint8_t		cpu_primary_start_32;
-extern uint8_t		cpu_primary_start_64;
-
 #endif /* RELOCATE_H */