mtd: spi-nor: fsl-quadspi: reset the module in the probe

The uboot may run the QuadSpi controler with command:
    #sf probe

So we should reset the module in the probe.
This patch also clear the pending interrupts which arised by the uboot
code.

Signed-off-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Frank Li <Frank.Li@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>