x86/srso: Add IBPB_BRTYPE support

stable inclusion
from stable-v5.10.189
commit df76a59feba549825f426cb1586bfa86b49c08fa
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I7RQ67
CVE: CVE-2023-20569

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=df76a59feba549825f426cb1586bfa86b49c08fa



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Upstream commit: 79113e40

Add support for the synthetic CPUID flag which "if this bit is 1,
it indicates that MSR 49h (PRED_CMD) bit 0 (IBPB) flushes all branch
type predictions from the CPU branch predictor."

This flag is there so that this capability in guests can be detected
easily (otherwise one would have to track microcode revisions which is
impossible for guests).

It is also needed only for Zen3 and -4. The other two (Zen1 and -2)
always flush branch type predictions by default.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

 Conflicts:
	arch/x86/include/asm/cpufeatures.h

Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>