In x86 architecture, word/doubleword/quadword aligned read/write on its boundary
is atomic, so we may remove atomic load/store.
As for atomic set/clear, use bitmap_set/claer seems more reasonable. After replace
them all, we could remove them too.
Tracked-On: #1842
Signed-off-by: Li, Fei1 <fei1.li@intel.com>