soc: imx: imx8mp-blk-ctrl: set HDMI LCDIF panic read hurry level

Same as done for both LCDIF interfaces in the MEDIA domain, set
the panic priority of the LCDIF instance in the HDMI domain to
the maximium NoC priority of 7 to minimize chances of display
underflows.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>