mtd: spinand: Call do_calibration when SPI NAND probes

commit 58e59c708a4a9de4e1a440a735ceccdde1be79a7 from
git://git.ti.com/ti-linux-kernel/ti-linux-kernel.git



Add the PHY calibration call during SPI NAND probe, so that, the PHY
is tuned with the optimal tuning point which enables controller to
run at higher speeds.

Load the known pattern to page buffer, and pass a page read op with
the do_calibration call.

Signed-off-by: Santhosh Kumar K <s-k6@ti.com>
Tested-by: Prasanth Babu Mantena <p-mantena@ti.com>
Signed-off-by: Xulin Sun <xulin.sun@windriver.com>