Currently all calls to `configure_linker_script()` specifies `-D<name>`
when calling `configure_linker_script()`.
This works well for the gcc pre-processed ld linker script templates,
but Zephyr also supports a CMake linker script generator which can be
used for ld scripts and armlink scatter files.
In this case, a `-D` must be stripped.
This commit changes this so that Zephyr CMake build system calls
`configure_linker_script()` without `-D`.
Thus the `LINKER_SCRIPT` choice can decide how this information should
be passed to underlying linker script functionality, that is `-D` for
linker script template and CMake variable for the CMake linker script
generator.
Signed-off-by: Torsten Rasmussen <Torsten.Rasmussen@nordicsemi.no>