I don't think this is an attractive approach to the problem,
because it results in us adding a bunch of meson rules to
simulate 'make install' within the build dir. This is undesirable
clutter IMHO, and can be solved more simply by just modifying the
qemu_find_file() method.
The core problem is the impl of qemu_find_file is taking the wrong
approach, in several ways, but mostly because of its use of a single
'data_dirs' array for all types of file. This is bad because it
has the assumption that build dir and install dir layouts match,
and second because when we add extra firmware data dirs, we don't
want this used for non-firmware files.
We need to separate out the handling of different types of resources
for this to work correctly.