of: address: Consolidate bus .map() functions

The bus .map() functions vary only by checking the flag cells values
and skipping over any flag cells to read the addresses. Otherwise they
all do the same reading 'ranges' address and size and returning the
address's offset if it is within the 'ranges' entry.

Refactor all the .map() functions to pass in the flag cell size so that
each bus can check the bus specific flags and then call a common
function to do everything else.

Acked-by: Herve Codina <herve.codina@bootlin.com>
Link: https://lore.kernel.org/r/20231026135358.3564307-3-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>