fix(tf-coverity): provide MBEDTLS_DIR path for rpi3 build

The MBEDTLS_DIR path is not set by default for the rpi3
build, so it is explicitly provided as a build parameter.

Change-Id: Ie95111eb12f1e291f3bc236f242557e52b539c87
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
1 file changed