spi: fix: Call mxs_reset_block() during DM/DTS probe

spi: fix: Call mxs_reset_block() during DM/DTS probe

Without this change the DM/DTS version of mxs_spi driver doesn't reset the
SPI IP block in probe.
As a result this driver (when used solely on U-Boot proper) relies on reset
performed by mxs spi driver in SPL.

In the use case where eMMC is used in SPL as a boot primary device, the
mxs_reset_block() is not called at all and DM/DTS aware SPI driver in
U-Boot proper is malfunctioning.

Signed-off-by: Lukasz Majewski <lukma@denx.de>