spi: microchip-core-qspi: set min_speed_hz during probe

The controller's minimum possible bus clock is 1/30 the rate of the
input clock. Naively set the minimum bus clock speed the controller
is capable of during probe, assuming that the rate will never reduce
further.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://patch.msgid.link/20250620-drained-widen-ac311bd5f172@spud
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: ConchuOD

drivers/spi/spi-microchip-core-qspi.c

@@ -562,6 +562,7 @@ static int mchp_coreqspi_probe(struct platform_device *pdev)
 	ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_RX_DUAL | SPI_RX_QUAD |
 			  SPI_TX_DUAL | SPI_TX_QUAD;
 	ctlr->dev.of_node = np;
+	ctlr->min_speed_hz = clk_get_rate(qspi->clk) / 30;
 
 	ret = devm_spi_register_controller(&pdev->dev, ctlr);
 	if (ret)