Temporarly solving the issue of
"differ from the size of original declaration [-Werror=lto-type-mismatch]
until linker is fixed in upcomming release of gcc.
Bug is reported by others, and will be fixed in next version of arm-gcc.
However, this patch makes it possible to use modmusic and modimage
with current compilers.
Alternativly, the code can be compiled with LTO=0, but uses valuable 9K
more on this already squeezed target (microbit).