x86/apic: Add Hygon Dhyana support

Add Hygon Dhyana support to the APIC subsystem. When running in 32 bit
mode, bigsmp should be enabled if there are more than 8 cores online.

Signed-off-by: Pu Wen <puwen@hygon.cn>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: tglx@linutronix.de
Cc: mingo@redhat.com
Cc: hpa@zytor.com
Cc: x86@kernel.org
Cc: thomas.lendacky@amd.com
Link: https://lkml.kernel.org/r/7a557265a8c7c9e842fe60f9d8e064458801aef3.1537533369.git.puwen@hygon.cn