linux-imx

of/unittest: replace 'selftest' with 'unittest'

This patch just replace the string 'selftest' with 'unittest'
in OF unittest and data and binding file.

I have tested it successfully on ARM.

Signed-off-by: Wang Long <long.wanglong@huawei.com>
Signed-off-by: Rob Herring <robh@kernel.org>