x86/speculation: Fix firmware entry SPEC_CTRL handling

stable inclusion
from stable-v4.19.266
commit 93f951062040f132968103bb5a070aaafde2865c
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I5GZ2Z


CVE: CVE-2022-29901

--------------------------------

commit e6aa1362 upstream.

The firmware entry code may accidentally clear STIBP or SSBD. Fix that.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Suleiman Souhlal <suleiman@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Lin Yujun <linyujun809@huawei.com>
Reviewed-by: Zhang Jianhua <chris.zjh@huawei.com>
Reviewed-by: Liao Chang <liaochang1@huawei.com>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>