dmaengine: imx-sdma: Remove platform data header

dmaengine: imx-sdma: Remove platform data header

Since commit 6c5f05a6cd88 ("ARM: imx3: Remove imx3 soc_init()")
there are no more users of struct sdma_script_start_addrs outside
of the driver itself, thus let's move the struct declaration just
to the driver source code and remove the header file as unused one.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Link: https://lore.kernel.org/r/20210620191103.156626-1-vz@mleia.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>