[PATCH 0/4] Allow absence of mach/io.h

[Eric Miao]

Introduce USE_DEFAULT_IO_H to allow default definitions of

  IO_SPACE_LIMIT
  __mem_pci()
  __io()

And most SoC can actually use these default definitions without the
need to have a specific mach/io.h. PXA and MMP are two examples in
the last patch, where the files are removed.