config path: @pkgdatadir@/mount.d/${arch}
config format:
Each line will start with 'ro' and 'rw' will be used, other lines will
be ignore, rest of line is out/path:in/path. e.g.
```
ro /some/path:/proc/cpuinfo
rw /some/some/path:/var/cache/pacman/pkg
```
For example, in the RISC-V port, if we use qemu-user to build, we need
to pass a parameter to makechrootpkg to map a correct /proc/cpuinfo, so
that software that relies on /proc/cpuinfo to obtain information can be
built normally.
Signed-off-by: Celeste Liu <CoelacanthusHex@gmail.com>
Kevin Mihelich
Celeste Liu
Levente Polyak