[PATCH] spi: imx: enable runtime pm support

[Nikita Shubin]

Hello Clark, 

This patch breaks spi-imx on imx7d.
Toradex Colibri imx7d spi reports with:

    [    4.258468] inv-mpu6000-spi spi2.0: I/O Error in PIO
    [    4.264269] inv-mpu6000-spi spi2.0: SPI transfer failed: -110
    [    4.264305] spi_master spi2: failed to transfer one message from queue

We are using spi-imx with dma.

Reverting your patch fixes this issue.

The baseline commit 951cbbc386ff01b50da4f46387e994e81d9ab431 (tag: v5.9.8, stable/linux-5.9.y)

Could you please give some comments on this issue ?