Unfortunately, at the time during in boot when we want to be setting up
the PMB entries, the kmem subsystem hasn't been initialised.

We now match pmb_map slots with pmb_entry_list slots. When we find an
empty slot in pmb_map, we set the bit, thereby acquiring the
corresponding pmb_entry_list entry. There is a benefit in using this
static array of struct pmb_entry's; we don't need to acquire any locks
in order to traverse the list of struct pmb_entry's.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>