optee-imx: clarify BSD license
Since upstream commit
14d4c007c4 ("common-licences: remove ambiguous
"BSD" license"), ambiguous "BSD" license has been removed from OE-Core.
This triggers the warning message in QA:
do_populate_lic_deploy: QA Issue: The license listed BSD was not in the
licenses collected for recipe optee-os [license-file-missing]
OP-TEE is licensed under "BSD-2-Clause" and license text clearly
identifies it.
Correct LICENSE variable to indicate proper License SPDX identifier.
Signed-off-by: Andrey Zhizhikin <andrey.z@gmail.com>
