of/address: Merge all of the bus translation code

of/address: Merge all of the bus translation code

Microblaze and PowerPC share a large chunk of code for translating
OF device tree data into usable addresses.  Differences between the two
consist of cosmetic differences, and the addition of dma-ranges support
code to powerpc but not microblaze.  This patch moves the powerpc
version into common code and applies many of the cosmetic (non-functional)
changes from the microblaze version.

Signed-off-by: Grant Likely <[email protected]>
Acked-by: Benjamin Herrenschmidt <[email protected]>
CC: Michal Simek <[email protected]>
CC: Wolfram Sang <[email protected]>
CC: Stephen Rothwell <[email protected]>