of/address: Clean up function declarations

This patch moves the declaration of of_get_address(), of_get_pci_address(),
and of_pci_address_to_resource() out of arch code and into the common
linux/of_address header file.

This patch also fixes some of the asm/prom.h ordering issues.  It still
includes some header files that it ideally shouldn't be, but at least the
ordering is consistent now so that of_* overrides work.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>