soc: imx: imx8mp-blk-ctrl: Fix typo of imx8m_blk_ctrl_of_match

Once set CONFIG_SOC_IMX8M as m, following error occurs:

drivers/soc/imx/imx8mp-blk-ctrl.c:747:25: error: ‘imx8m_blk_ctrl_of_match’
undeclared here (not in a function); did you mean ‘imx8mp_blk_ctrl_of_match’?
  747 | MODULE_DEVICE_TABLE(of, imx8m_blk_ctrl_of_match);
      |                         ^~~~~~~~~~~~~~~~~~~~~~~

Fix the typo.

Signed-off-by: Jindong Yue <jindong.yue@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>