davinci: Move pinmux setup info to SoC infrastructure

The pinmux register base and setup can be different for different
SoCs so move the pinmux reg base, pinmux table (and its size) to
the SoC infrastructure.

Signed-off-by: Mark A. Greer <mgreer@mvista.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>