cris: Fix conflicting types for _etext, _edata, _end

Include asm/sections.h header which contains the correct
types for _etext, _edata and _end - char arrays.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>