MLK-15001-11 gpu: Move ipuv3 and dpu to imx folder

IPUv3 and DPU are both i.MX display processing units.
To organize the driver code better, let's introduce the imx folder for them.
Later, we may put more drivers into this folder, e.g., the prefetch engines.

Signed-off-by: Liu Ying <victor.liu@nxp.com>

drivers/gpu/Makefile

@@ -3,5 +3,4 @@
 # to ensure this currently.
 obj-$(CONFIG_TEGRA_HOST1X)	+= host1x/
 obj-y			+= drm/ vga/
-obj-$(CONFIG_IMX_IPUV3_CORE)	+= ipu-v3/
-obj-$(CONFIG_IMX_DPU_CORE)	+= dpu/
+obj-y			+= imx/

drivers/gpu/imx/Kconfig

@@ -0,0 +1,2 @@
+source drivers/gpu/imx/ipu-v3/Kconfig
+source drivers/gpu/imx/dpu/Kconfig

drivers/gpu/imx/Makefile

@@ -0,0 +1,2 @@
+obj-$(CONFIG_IMX_IPUV3_CORE)	+= ipu-v3/
+obj-$(CONFIG_IMX_DPU_CORE)	+= dpu/

drivers/video/Kconfig

@@ -16,8 +16,7 @@ source "drivers/char/agp/Kconfig"
 source "drivers/gpu/vga/Kconfig"
 
 source "drivers/gpu/host1x/Kconfig"
-source "drivers/gpu/ipu-v3/Kconfig"
-source "drivers/gpu/dpu/Kconfig"
+source "drivers/gpu/imx/Kconfig"
 
 source "drivers/gpu/drm/Kconfig"