Instead of holding SPEC-variable dependent files and directories inline
within the repository structure, move them into 'spec' subdirectories
at the corresponding levels, e.g.:
repos/base/include/spec
repos/base/mk/spec
repos/base/lib/mk/spec
repos/base/src/core/spec
...
Moreover, this commit removes the 'platform' directories. That term was
used in an overloaded sense. All SPEC-relative 'platform' directories are
now named 'spec'. Other files, like for instance those related to the
kernel/architecture specific startup library, where moved from 'platform'
directories to explicit, more meaningful places like e.g.: 'src/lib/startup'.
Fix#1673
The base-hw kernel on x86_64 currently assumes 254 MiB of RAM. The RAM
region is subtracted from the I/O mem allocator and therefore this range
is not available for device I/O.
If qemu is started with -m 128, the region for (emulated) PCI config
space access lies within this region and I/O mem allocation in the
pci_drv will fail. Giving qemu more RAM moves the PCI config space out
of the 254 MiB region, making the run/libc_ffat scenario with acpi work.
