dm: spi: Read default speed and mode values from DT

In case of DT boot, don't read default speed and mode for SPI from
CONFIG_*, instead read from DT node. This will make sure that boards
with multiple SPI/QSPI controllers can be probed at different
bus frequencies and SPI modes.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Mugunthan V N <mugunthanvnm@ti.com>
Reviewed-by: Jagan Teki <jteki@openedev.com>

cmd/sf.c

@@ -88,6 +88,8 @@ static int do_spi_flash_probe(int argc, char * const argv[])
 #ifdef CONFIG_DM_SPI_FLASH
 	struct udevice *new, *bus_dev;
 	int ret;
+	/* In DM mode defaults will be taken from DT */
+	speed = 0, mode = 0;
 #else
 	struct spi_flash *new;
 #endif