ARM: iop32x: merge everything into mach-iop32x/

ARM: iop32x: merge everything into mach-iop32x/

Various bits of iop32x are now in their traditional locations in plat-iop,
mach-iop/include/mach/ and in include/asm/mach/hardware. As nothing
outside of the iop32x mach code references these any more, this can all
be moved into one place now.

The only remaining things in the include/mach/ directory are now the
NR_IRQS definition, the entry-macros.S file and the the decompressor
uart access. After the irqchip code has been converted to SPARSE_IRQ
and GENERIC_IRQ_MULTI_HANDLER, it can be moved to ARCH_MULTIPLATFORM.

Link: https://lore.kernel.org/r/20190809163334.489360-7-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>