m68k: reorganize Kconfig options to improve mmu/non-mmu selections

m68k: reorganize Kconfig options to improve mmu/non-mmu selections

The current mmu and non-mmu Kconfig files can be merged to form
a more general selection of options. The current break up of options
is due to the simple brute force merge from the m68k and m68knommu
arch directories.

Many of the options are not at all specific to having the MMU enabled
or not. They are actually associated with a particular CPU type or
platform type.

Ultimately as we support all processors with the MMU disabled we need
many of these options to be selectable without the MMU option enabled.
And likewise some of the ColdFire processors, which currently are only
supported with the MMU disabled, do have MMU hardware, and will need
to have options selected on CPU type, not MMU disabled.

This patch removes the old mmu and non-mmu Kconfigs and instead breaks
up the configuration into four areas: cpu, machine, bus, devices.

The Kconfig.cpu lists all the options associated with selecting a CPU,
and includes options specific to each CPU type as well.

Kconfig.machine lists all options associated with selecting a machine
type. Almost always the machines selectable is restricted by the chosen
CPU.

Kconfig.bus contains options associated with selecting bus types on the
various machine types. That includes PCI bus, PCMCIA bus, etc.

Kconfig.devices contains options for drivers and driver associated
options.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>