package/optee-test: add upstream patch to work with python 3.x

Fixes:
TypeError: cannot use a str to initialize an array with typecode 'B'
  File "../../scripts/file_to_c.py", line 32, in main
    for x in array.array("B", inf.read()):
    for x in array.array("B", inf.read()):
TypeError: cannot use a str to initialize an array with typecode 'B'
TypeError: cannot use a str to initialize an array with typecode 'B'

Signed-off-by: Romain Naour <romain.naour@smile.fr>
[Peter: reword commit message]
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>