Volatile configuration register are a different set of configuration
registers, i.e. they differ from the status registers. A different
SPI instruction is required to write to these registers. Any changes
to the Volatile Configuration Register get transferred directly to
the Internal Configuration Register and instantly reflect on the
device operation.
In Winbond W35N01JW, these volatile configuration register must be
configured in order to switch to Octal DTR SPI mode.
Add support for writing to volatile configuration registers using a
new WRITE_VCR_OP template.
Datasheet:
https://www.winbond.com/export/sites/winbond/datasheet/W35N01JW_Datasheet_Brief.pdf
Signed-off-by: Apurva Nandan <a-nandan@ti.com>