Documentation/ABI: Mention retbleed vulnerability info file for sysfs

stable inclusion
from stable-v5.10.140
commit 7ca73d0a16e382ae365d5fab7e2e47f753d18f35
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I63FTT

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7ca73d0a16e382ae365d5fab7e2e47f753d18f35

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

commit 00da0cb3 upstream.

While reporting for the AMD retbleed vulnerability was added in

  6b80b59b ("x86/bugs: Report AMD retbleed vulnerability")

the new sysfs file was not mentioned so far in the ABI documentation for
sysfs-devices-system-cpu. Fix that.

Fixes: 6b80b59b ("x86/bugs: Report AMD retbleed vulnerability")
Signed-off-by: NSalvatore Bonaccorso <carnil@debian.org>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220801091529.325327-1-carnil@debian.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: NWei Li <liwei391@huawei.com>

Documentation/ABI/testing/sysfs-devices-system-cpu

@@ -511,6 +511,7 @@ What:		/sys/devices/system/cpu/vulnerabilities
 		/sys/devices/system/cpu/vulnerabilities/tsx_async_abort
 		/sys/devices/system/cpu/vulnerabilities/itlb_multihit
 		/sys/devices/system/cpu/vulnerabilities/mmio_stale_data
+		/sys/devices/system/cpu/vulnerabilities/retbleed
 Date:		January 2018
 Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
 Description:	Information about CPU vulnerabilities