spi: stm32-ospi: Fix DMA channel leak on stm32_ospi_dma_setup() failure

spi: stm32-ospi: Fix DMA channel leak on stm32_ospi_dma_setup() failure

When stm32_ospi_dma_setup() fails, the DMA channels allocated by
stm32_ospi_get_resources() were never released. Add proper cleanup
in the error path.

Fixes: e35a7607e05d ("spi: stm32-ospi: Set DMA maxburst dynamically")
Signed-off-by: Felix Gu <ustc.gu@gmail.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Link: https://patch.msgid.link/20260329-stm32-ospi-v1-2-142122466412@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>