am33xx: refactor am33xx mux support and add ti814x support

AM33XX and TI814X have a similar mux though the pinmux register
layout and address space differ. Add a separate ti814x mux include
to support the TI814X-specific differences.

Signed-off-by: Matt Porter <mporter@ti.com>
Reviewed-by: Tom Rini <trini@ti.com>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
3 files changed