spi: sn-f-ospi: Fix resource leak in f_ospi_probe()

spi: sn-f-ospi: Fix resource leak in f_ospi_probe()

In f_ospi_probe(), when num_cs validation fails, it returns without
calling spi_controller_put() on the SPI controller, which causes a
resource leak.

Use devm_spi_alloc_host() instead of spi_alloc_host() to ensure the
SPI controller is properly freed when probe fails.

Fixes: 1b74dd64c861 ("spi: Add Socionext F_OSPI SPI flash controller driver")
Signed-off-by: Felix Gu <ustc.gu@gmail.com>
Link: https://patch.msgid.link/20260319-sn-f-v1-1-33a6738d2da8@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>