Input: edt-ft5x06 - convert to use simple_open()

This removes an open coded simple_open() function and
replaces file operations references to the function
with simple_open() instead.

dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch

)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>