Fix issue with DEV_MODE=OFF case
Fix issue with DEV_MODE=OFF case

When DEV_MODE=OFF, link_to_source() was being called with
a full path in the build directory, rather than just a base
name starting at "suites/" as was intended. Fix this by
generating a list of base names and using that for
link_to_source(), then deriving full paths afterwards.

Signed-off-by: David Horstmann <0386b5e8f8e5ea8a58d40026a5369df20e1c750d@arm.com>

NXPmicro/mbedtls,NXPmicro/mbedtls,NXPmicro/mbedtls,Mbed-TLS/mbedtls,ARMmbed/mbedtls,ARMmbed/mbedtls,Mbed-TLS/mbedtls,ARMmbed/mbedtls,Mbed-TLS/mbedtls,Mbed-TLS/mbedtls,ARMmbed/mbedtls,NXPmicro/mbedtls