imx: imx8mq: default select CLK_IMX8MQ

Since the power domain driver default select CONFIG_CLK, so we will
meet lots failures without CLK_IMX8MQ, so default select it.

Fixes: commit 4eb82c2e ("imx: power-domain: Get rid of SMCCC dependency")
Signed-off-by: Peng Fan <peng.fan@nxp.com>