UKSM: added documentation

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
UKSM: added sradix-tree

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
UKSM: added uksm.h

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
UKSM: added uksm.c

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
UKSM: Add changes for uksm building

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
UKSM: strict_strtoul obsoleted -> kstrtoul

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
UKSM: Remove custom memcmp

x86 memcmp can be moved to ../arch/x86/string*.h
We no need internal memcmp comparasion, if we can provide it to whole kernel

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
UKSM: Merge memcmp_pages into pages_identical.patch

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>