dmaengine: imx-sdma: Allow imx8m for imx7 FW revs

dmaengine: imx-sdma: Allow imx8m for imx7 FW revs

The revision of the imx-sdma IP that is in the i.MX8M series is the
same is that as that in the i.MX7 series but the imx7d MODULE_FIRMWARE
directive is wrapped in a condiditional which means it's not defined
when built for aarch64 SOC_IMX8M platforms and hence you get the
following errors when the driver loads on imx8m devices:

imx-sdma 302c0000.dma-controller: Direct firmware load for imx/sdma/sdma-imx7d.bin failed with error -2
imx-sdma 302c0000.dma-controller: external firmware not found, using ROM firmware

Add the SOC_IMX8M into the check so the firmware can load on i.MX8.

Fixes: 1474d48bd639 ("arm64: dts: imx8mq: Add SDMA nodes")
Fixes: 941acd566b18 ("dmaengine: imx-sdma: Only check ratio on parts that support 1:1")
Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Cc: stable@vger.kernel.org   # v5.2+
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Link: https://lore.kernel.org/r/20220606161034.3544803-1-pbrobinson@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>