CONFIG_PPC_MULTIPLATFORM is a remain of the pre-powerpc days and isn't
really meaningful anymore. It was basically equivalent to PPC64 || 6xx.

This removes it along with the following changes:

 - 32-bit platforms that relied on PPC32 && PPC_MULTIPLATFORM now rely
   on 6xx which is what they want anyway.

 - A new symbol, PPC_BOOK3S, is defined that represent compliance with
   the "Server" variant of the architecture. This is set when either 6xx
   or PPC64 is set and open the door for future BOOK3E 64-bit.

 - 64-bit platforms that relied on PPC64 && PPC_MULTIPLATFORM now use
   PPC64 && PPC_BOOK3S

 - A separate and selectable CONFIG_PPC_OF_BOOT_TRAMPOLINE option is now
   used to control the use of prom_init.c
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The TSI108 code and the 32 bit powermac and chrp platforms
have dependency on PCI that is not easy or desirable to get rid
of.

The easiest fix is to always select CONFIG_PCI if one of those
platforms is enabled.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

Rename MPIC_BROKEN_U3 to something a little more descriptive. Its
effect is to enable support for HT irqs behind the PCI-X/HT bridge on
U3/U4 (aka. CPC9x5) parts.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Cleaning up arch/powerpc/Kconfig platform support.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>