spi: mxs: support effective_speed_hz

Setting spi_transfer->effective_speed_hz in transfer_one_message so that
SPI client driver can use it.

Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://patch.msgid.link/20241209111316.4767-1-wahrenst@gmx.net
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: lategoodbye

drivers/spi/spi-mxs.c

@@ -381,6 +381,8 @@ static int mxs_spi_transfer_one(struct spi_controller *host,
 		if (status)
 			break;
 
+		t->effective_speed_hz = ssp->clk_rate;
+
 		/* De-assert on last transfer, inverted by cs_change flag */
 		flag = (&t->transfer_list == m->transfers.prev) ^ t->cs_change ?
 		       TXRX_DEASSERT_CS : 0;