dt-bindings: soc: imx-blk-ctrl: add i.MX91 blk-ctrl compatible

dt-bindings: soc: imx-blk-ctrl: add i.MX91 blk-ctrl compatible

Add new compatible string "fsl,imx91-media-blk-ctrl" for i.MX91,
which has different input clocks compared to i.MX93. Update the
clock-names list and handle it in the if-else branch accordingly.

Keep the same restriction for the existed compatible strings.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Joy Zou <joy.zou@nxp.com>
Link: https://lore.kernel.org/r/20250806114119.1948624-3-joy.zou@nxp.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>