soc/amd/glinda: Enable x86_64 support

The code compiles and works fine in x86_64. Thus allow the user
to use x86_64.

TEST: Booted on amd/birman+ to OS using EDK2 as payload.

Change-Id: If1b5d91a376770c0f0e1a4ee46dd625b401fbfa6
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/86581
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Ana Carolina Cabral <ana.cpmelo95@gmail.com>
Reviewed-by: Maximilian Brune <maximilian.brune@9elements.com>

src/soc/amd/glinda/Kconfig

@@ -90,6 +90,7 @@ config SOC_AMD_GLINDA
 	select VBOOT_DEFINE_WIDEVINE_COUNTERS if VBOOT_STARTS_BEFORE_BOOTBLOCK
 	select X86_AMD_FIXED_MTRRS
 	select X86_INIT_NEED_1_SIPI
+	select HAVE_X86_64_SUPPORT
 	help
 	  AMD Glinda support