soc: sunxi: sram: Prevent the driver from being unbound

This driver exports a regmap tied to the platform device (as opposed to
a syscon, which exports a regmap tied to the OF node). Because of this,
the driver can never be unbound, as that would destroy the regmap. Use
builtin_platform_driver_probe() to enforce this limitation.

Fixes: 5828729b ("soc: sunxi: export a regmap for EMAC clock reg on A64")
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20220815041248.53268-5-samuel@sholland.org

drivers/soc/sunxi/sunxi_sram.c

@@ -330,7 +330,7 @@ static struct regmap_config sunxi_sram_emac_clock_regmap = {
 	.writeable_reg	= sunxi_sram_regmap_accessible_reg,
 };
 
-static int sunxi_sram_probe(struct platform_device *pdev)
+static int __init sunxi_sram_probe(struct platform_device *pdev)
 {
 	struct dentry *d;
 	struct regmap *emac_clock;
@@ -410,9 +410,8 @@ static struct platform_driver sunxi_sram_driver = {
 		.name		= "sunxi-sram",
 		.of_match_table	= sunxi_sram_dt_match,
 	},
-	.probe	= sunxi_sram_probe,
 };
-module_platform_driver(sunxi_sram_driver);
+builtin_platform_driver_probe(sunxi_sram_driver, sunxi_sram_probe);
 
 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
 MODULE_DESCRIPTION("Allwinner sunXi SRAM Controller Driver");