MIPS: Malta: Fix PCI southbridge legacy resource reservations

Covering the PCI southbridge legacy port I/O range with a northbridge
resource reservation prevents MIPS Malta platform code from claiming its
standard legacy resources.  This is because request_resource() calls
cause a clash with the previous reservation and consequently fail.

Change to using insert_resource() so as to prevent the clash, switching
the legacy reservations from:

  00000000-00ffffff : MSC PCI I/O
    00000020-00000021 : pic1
    00000070-00000077 : rtc0
    000000a0-000000a1 : pic2
    [...]

to:

  00000000-00ffffff : MSC PCI I/O
    00000000-0000001f : dma1
    00000020-00000021 : pic1
    00000040-0000005f : timer
    00000060-0000006f : keyboard
    00000070-00000077 : rtc0
    00000080-0000008f : dma page reg
    000000a0-000000a1 : pic2
    000000c0-000000df : dma2
    [...]

Fixes: ae81aad5 ("MIPS: PCI: Use pci_enable_resources()")
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: stable@vger.kernel.org # v6.18+
Link: https://patch.msgid.link/alpine.DEB.2.21.2510212001250.8377@angie.orcam.me.uk