sh: import missing private libraries from Linux 3.19

SuperH is supposed to support the Private Library feature, but it is
actually not working.

If CONFIG_USE_PRIVATE_LIBGCC is enabled, the build fails for the
undefined references to '__sdivsi3_i4i' and '__udivsi3_i4i'.

To fix this error, import missing libraries from Linux 3.19
and adjust them for U-Boot:
  - Remove "#include <linux/module.h>" and "EXPORT_SYMBOL(...)"
  - Use SPDX-License-Identifier
  - Remove white space

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>