[PATCH] [POWERPC] i2c: fix build breakage introduced by OF helpers

[Paul Mackerras]

Jochen Friedrich writes:

> Fix build breakage introduced in commit
> "[POWERPC] i2c: OF helpers for the i2c API".
> If i2c-core is compiled as module, the helper needs to be
> compiled as module, as well. Rename i2c.c to of_i2c.c to
> avoid name space conflict.

Actually, since only powerpc has irq_of_parse_and_map, I'm now
inclined to think that drivers/of/i2c.c should live under arch/powerpc
for now, or at the least its option should depend on PPC_OF.

Paul.