drm/fsl-dcu: Constify struct regmap_config

`fsl_tcon_regmap_config` is not modified and can be declared as const to
move its data to a read-only section.

Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240925-drm-const-regmap-v1-2-e609d502401b@gmail.com


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

drivers/gpu/drm/fsl-dcu/fsl_tcon.c

@@ -29,7 +29,7 @@ void fsl_tcon_bypass_enable(struct fsl_tcon *tcon)
 			   FSL_TCON_CTRL1_TCON_BYPASS);
 }
 
-static struct regmap_config fsl_tcon_regmap_config = {
+static const struct regmap_config fsl_tcon_regmap_config = {
 	.reg_bits = 32,
 	.reg_stride = 4,
 	.val_bits = 32,