Revert "x86/cpufeatures: Add FEATURE_ZEN"

BugLink: https://bugs.launchpad.net/bugs/1791080

This reverts commit c03cef66 to
be replaced by upstream stable variant.

[smb: Not reverting the feature bit definition, would come back
      in the same place]
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

arch/x86/kernel/cpu/amd.c

@@ -815,7 +815,6 @@ static void init_amd(struct cpuinfo_x86 *c)
 		set_cpu_bug(c, X86_BUG_AMD_APIC_C1E);
 
 	if (c->x86 == 0x17) {
-		set_cpu_cap(c, X86_FEATURE_ZEN);
 		/*
 		 * Fix erratum 1076: CPB feature bit not being set in CPUID.
 		 * It affects all up to and including B1.