drm/mediatek: Separate mtk_mipi_tx to an independent module

mtk_mipi_tx is a part of mtk_drm module, but phy driver should be an
independent module rather than be part of drm module, so separate the phy
driver to an independent module.

Signed-off-by: Chun-Kuang Hu <[e-mail]>

drivers/gpu/drm/mediatek/Kconfig

···
 	select DRM_PANEL
 	select MEMORY
 	select MTK_SMI
+	select PHY_MTK_MIPI_DSI
 	select VIDEOMODE_HELPERS
 	help
 	  Choose this option if you have a Mediatek SoCs.
···
 	select PHY_MTK_HDMI
 	help
 	  DRM/KMS HDMI driver for Mediatek SoCs
+
+config PHY_MTK_MIPI_DSI
+	tristate "Mediatek MIPI-DSI-PHY Driver"
+	depends on ARCH_MEDIATEK && OF
+	select GENERIC_PHY
+	help
+	  Support MIPI DSI PHY for Mediatek SoCs.

drivers/gpu/drm/mediatek/Makefile

···
 		  mtk_drm_gem.o \
 		  mtk_drm_plane.o \
 		  mtk_dsi.o \
-		  mtk_mipi_tx.o \
-		  mtk_mt8173_mipi_tx.o \
-		  mtk_mt8183_mipi_tx.o \
 		  mtk_dpi.o
 
 obj-$(CONFIG_DRM_MEDIATEK) += mediatek-drm.o
···
 			  mtk_hdmi_ddc.o
 
 obj-$(CONFIG_DRM_MEDIATEK_HDMI) += mediatek-drm-hdmi.o
+
+phy-mtk-mipi-dsi-drv-objs := mtk_mipi_tx.o \
+			     mtk_mt8173_mipi_tx.o \
+			     mtk_mt8183_mipi_tx.o
+
+obj-$(CONFIG_PHY_MTK_MIPI_DSI) += phy-mtk-mipi-dsi-drv.o

drivers/gpu/drm/mediatek/mtk_drm_drv.c

···
 	&mtk_disp_rdma_driver,
 	&mtk_dpi_driver,
 	&mtk_drm_platform_driver,
-	&mtk_mipi_tx_driver,
 	&mtk_dsi_driver,
 };
 

drivers/gpu/drm/mediatek/mtk_drm_drv.h

···
 extern struct platform_driver mtk_disp_rdma_driver;
 extern struct platform_driver mtk_dpi_driver;
 extern struct platform_driver mtk_dsi_driver;
-extern struct platform_driver mtk_mipi_tx_driver;
 
 #endif /* MTK_DRM_DRV_H */

drivers/gpu/drm/mediatek/mtk_mipi_tx.c

···
 		.of_match_table = mtk_mipi_tx_match,
 	},
 };
+module_platform_driver(mtk_mipi_tx_driver);
 
+MODULE_DESCRIPTION("MediaTek MIPI TX Driver");
+MODULE_LICENSE("GPL v2");