Documentation/x86: Add buslock.rst

mainline inclusion
from mainline-v5.12-rc4
commit 1897907c
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I5G10C
CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/


commit/?id=1897907c

Intel-SIG: commit 1897907c Documentation/x86: Add buslock.rst

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

Add buslock.rst to explain bus lock problem and how to detect and
handle it.

[ tglx: Included it into index.rst and added the missing include ... ]

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20210419214958.4035512-2-fenghua.yu@intel.com



(cherry picked from commit 1897907c)
Signed-off-by: Ethan Zhao <haifeng.zhao@linux.intel.com>