ARM: spear: remove most mach/*.h header contents

The register and irq definitions in mach/*.h for spear3xx and
spear6xx are now mostly obsolete, after the platforms have been
converted to device tree based probing and the data is now
part of the device tree files.

The misc_regs.h contents are moved into clock.c because that is
the only user, aside from the DMA_CHN_CFG that should eventually
get handled differently. Some of the contents of mach/spear.h
still remain, because they are used to set up the static map table,
timer, uart and auxdata tables, but almost everything got removed.
We might remove everything but the map table as the DT conversion
completes, but that is not a priority. I've also made sure to
make both copies of spear.h more or less identical so we can
eventually combine them.

The spear3?0.h files were only used by the spear3?0.c files, so I
merged the contents in there and removed the bits that were unused.
This is something that should still be looked at.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Viresh Kumar <viresh.kumar@st.com>