spi: airoha: remove unnecessary switch to non-dma mode

spi: airoha: remove unnecessary switch to non-dma mode

The code switches to dma at the start of dirmap operation and returns
to non-dma at the end of dirmap operation, so an additional switch to
non-dma at the start of dirmap write is not required.

Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://patch.msgid.link/20251012121707.2296160-5-mikhail.kshevetskiy@iopsys.eu
Signed-off-by: Mark Brown <broonie@kernel.org>