ARM: omap1: move mach/*.h into mach directory

Most of the header files are no longer referenced from outside
arch/arm/mach-omap1, so move them all to that place directly
and change their users to use the new location.

The exceptions are:

- mach/compress.h is used by the core architecture code
- mach/serial.h is used by mach/compress.h

The mach/memory.h is empty and gets removed in the process,
avoiding the need for CONFIG_NEED_MACH_MEMORY_H.

Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>