spi: atmel-quadspi: Move common code outside of if else

QSPI_IFR is set as the last QSPI Instruction Frame register
regardless of the sama5d2 or sam9x60 version of the IP. Move
the writing of QSPI_IFR outside of the IP specific code.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20201207135959.154124-5-tudor.ambarus@microchip.com


Signed-off-by: Mark Brown <broonie@kernel.org>