spi: imx: Remove the use of property "fsl, spi-num-chipselects"
The "fsl,spi-num-chipselects" property will be marked obsolete soon.
This patch updates the driver to be ready to such changes.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>