memory: aemif: allow passing device lookup table as platform data

TI aemif driver creates its own subnodes of the device tree in order
to guarantee that all child devices are probed after the AEMIF timing
parameters are configured.

Some devices (e.g. da850) use struct of_dev_auxdata for clock lookup
but nodes created from within the aemif driver can't access the lookup
table.

Create a platform data structure that holds a pointer to
of_dev_auxdata so that we can use it with of_platform_populate().

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>