Documentation: KVM: Update AMD memory encryption link

Update AMD memory encryption white-paper document link.
Previous link is not available. Update new available link.
Signed-off-by: Wyes Karny <wyes.karny@amd.com>
Reviewed-by: Carlos Bilbao <carlos.bilbao@amd.com>
Link: https://lore.kernel.org/r/20230125175948.21100-1-wyes.karny@amd.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/virt/kvm/x86/amd-memory-encryption.rst

@@ -440,7 +440,7 @@ References
 
 See [white-paper]_, [api-spec]_, [amd-apm]_ and [kvm-forum]_ for more info.
 
-.. [white-paper] http://amd-dev.wpengine.netdna-cdn.com/wordpress/media/2013/12/AMD_Memory_Encryption_Whitepaper_v7-Public.pdf
+.. [white-paper] https://developer.amd.com/wordpress/media/2013/12/AMD_Memory_Encryption_Whitepaper_v7-Public.pdf
 .. [api-spec] https://support.amd.com/TechDocs/55766_SEV-KM_API_Specification.pdf
 .. [amd-apm] https://support.amd.com/TechDocs/24593.pdf (section 15.34)
 .. [kvm-forum]  https://www.linux-kvm.org/images/7/74/02x08A-Thomas_Lendacky-AMDs_Virtualizatoin_Memory_Encryption_Technology.pdf