drm/komeda: Add support for Arm China Linlon-D6

Arm China Linlon-D6 is register-compatible with the Mali-D71 display
pipeline for the purpose of basic modesetting.

On Linlon-D6, the PRODUCT_ID register is located at the same offset as on
Mali-D71 and reports 0x0060. The IP also exposes the same Komeda top-level
block layout expected by the existing d71_identify() probing flow, so we
can reuse the D71 function table to bring up the display engine.

Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Signed-off-by: Cunyuan Liu <cunyuan.liu@cixtech.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://patch.msgid.link/20260313033119.33686-4-cunyuan.liu@cixtech.com

drivers/gpu/drm/arm/display/include/malidp_product.h

@@ -20,6 +20,7 @@
 /* Mali-display product IDs */
 #define MALIDP_D71_PRODUCT_ID	0x0071
 #define MALIDP_D32_PRODUCT_ID	0x0032
+#define LINLONDP_D6_PRODUCT_ID	0x0060
 
 union komeda_config_id {
 	struct {

drivers/gpu/drm/arm/display/komeda/d71/d71_dev.c

@@ -628,6 +628,7 @@ d71_identify(u32 __iomem *reg_base, struct komeda_chip_info *chip)
 	switch (product_id) {
 	case MALIDP_D71_PRODUCT_ID:
 	case MALIDP_D32_PRODUCT_ID:
+	case LINLONDP_D6_PRODUCT_ID:
 		funcs = &d71_chip_funcs;
 		break;
 	default:

drivers/gpu/drm/arm/display/komeda/komeda_drv.c

@@ -104,6 +104,7 @@ static int komeda_platform_probe(struct platform_device *pdev)
 static const struct of_device_id komeda_of_match[] = {
 	{ .compatible = "arm,mali-d71", .data = d71_identify, },
 	{ .compatible = "arm,mali-d32", .data = d71_identify, },
+	{ .compatible = "armchina,linlon-d6", .data = d71_identify, },
 	{},
 };