x86/events: Add Hygon Dhyana support to PMU infrastructure

The PMU architecture for the Hygon Dhyana CPU is similar to the AMD
Family 17h one. To support it, call amd_pmu_init() to share the AMD PMU
initialization flow, and change the PMU name to "HYGON".

The Hygon Dhyana CPU supports both legacy and extension PMC MSRs (perf
counter registers and event selection registers), so add Hygon Dhyana
support in the similar way as AMD does.

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/9d93ed54a975f33ef7247e0967960f4ce5d3d990.1537533369.git.puwen@hygon.cn