Revert "spi: zynq_qspi: Use dummy buswidth in dummy byte calculation"

Revert "spi: zynq_qspi: Use dummy buswidth in dummy byte calculation"

This reverts commit e09784728689de7949d4cdd559a9590e0bfcc702. The
commit wrongly divides the dummy bytes by dummy bus width to calculate
the dummy bytes. The framework already converts the dummy cycles to the
number of bytes and the controller use the SPI flash command to
determine the dummy cycles via the address width.

Signed-off-by: Stefan Herbrechtsmeier <[email protected]>
Acked-by: Ashok Reddy Soma <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Michal Simek <[email protected]>