staging/ion: add Allwinner ION "secure" heap **not for mainline**

staging/ion: add Allwinner ION "secure" heap **not for mainline**

Dumped from:
  https://github.com/loboris/OrangePI-Kernel/tree/master/linux-3.4
  0cc8d855adb
  Author: Sunny <sunny@allwinnertech.com> for Allwinner.

Changes made on original "secure heap" implementation:
- minor coding style: fix includes, empty lines and overlong lines,
  indentation, comment layout.
- Original path modified the ion uapi. We do not attempt to modify
  uapi/ion.h. "secure" (or "domain") heaps are under ID
  ION_HEAP_TYPE_CUSTOM + 1 (legacy 'secure heap type' value).

Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
Reviewed-by: Joakim Bech <joakim.bech@linaro.org>
(cherry picked from commit e31dd54997b050b6a6965d7cfbc795492256847c
 linaro repo https://github.com/linaro-swg/linux.git
 tag optee-v4.9-20171005)