yocto/parsec-se-driver: Add mbedtls to SRC_URI

parsec-se-driver does not support MbedTLS 3.6.0, so instead of
using the meta-oe mbedtls recipe in meta-oe, download the specific
version of MbedTLS required in the recipe itself.

Signed-off-by: Peter Hoyes <peter.hoyes@arm.com>