spi: sh-msiof: Convert to use GPIO descriptors

Convert GPIO chip selects in the Renesas MSIOF SPI driver from legacy
GPIO numbers to GPIO descriptors.

Notes:
  - The board file for the SH7724-based Ecovec24 development board now
    registers a GPIO descriptor lookup, instead of passing a GPIO number
    through controller_data,
  - sh_msiof_get_cs_gpios() must release all GPIOs, else
    spi_get_gpio_descs() cannot claim them during SPI controller
    registration.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>

arch/sh/boards/mach-ecovec24/setup.c

@@ -806,7 +806,6 @@ static struct spi_board_info spi_bus[] = {
 		.platform_data	= &mmc_spi_info,
 		.max_speed_hz	= 5000000,
 		.mode		= SPI_MODE_0,
-		.controller_data = (void *) GPIO_PTM4,
 	},
 };
 
@@ -838,6 +837,14 @@ static struct platform_device msiof0_device = {
 	.resource	= msiof0_resources,
 };
 
+static struct gpiod_lookup_table msiof_gpio_table = {
+	.dev_id = "spi_sh_msiof.0",
+	.table = {
+		GPIO_LOOKUP("sh7724_pfc", GPIO_PTM4, "cs", GPIO_ACTIVE_HIGH),
+		{ },
+	},
+};
+
 #endif
 
 /* FSI */
@@ -1296,12 +1303,11 @@ static int __init arch_setup(void)
 	gpio_request(GPIO_FN_MSIOF0_TXD, NULL);
 	gpio_request(GPIO_FN_MSIOF0_RXD, NULL);
 	gpio_request(GPIO_FN_MSIOF0_TSCK, NULL);
-	gpio_request(GPIO_PTM4, NULL); /* software CS control of TSYNC pin */
-	gpio_direction_output(GPIO_PTM4, 1); /* active low CS */
 	gpio_request(GPIO_PTB6, NULL); /* 3.3V power control */
 	gpio_direction_output(GPIO_PTB6, 0); /* disable power by default */
 
 	gpiod_add_lookup_table(&mmc_spi_gpio_table);
+	gpiod_add_lookup_table(&msiof_gpio_table);
 	spi_register_board_info(spi_bus, ARRAY_SIZE(spi_bus));
 #endif