drm/exynos: trigger build of all modules

Add COMPILE_TEST dependency to force exynos driver to
built for more than arm and to built modules
that otherwise required other symbols to be de-selected.

This will increase build coverage of the exynos driver
thus allowing most trivial build errors to be detected/fixed early.

This introduces one warning when built using sh:
exynos7_drm_decon.c: In function ‘decon_remove’:
exynos7_drm_decon.c:769:24: warning: unused variable ‘ctx’
  struct decon_context *ctx = dev_get_drvdata(&pdev->dev);

This is due to the definition of iounmap() in sh,
and nothing that exynos driver can fix.

Include fix of exynos build for alpha.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Inki Dae <inki.dae@samsung.com>
Cc: Joonyoung Shim <jy0922.shim@samsung.com>
Cc: Seung-Woo Kim <sw0312.kim@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Jingoo Han <jingoohan1@gmail.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/Kconfig

 # SPDX-License-Identifier: GPL-2.0-only
 config DRM_EXYNOS
 	tristate "DRM Support for Samsung SoC EXYNOS Series"
-	depends on OF && DRM && (ARCH_S3C64XX || ARCH_S5PV210 || ARCH_EXYNOS || ARCH_MULTIPLATFORM)
+	depends on OF && DRM && (ARCH_S3C64XX || ARCH_S5PV210 || ARCH_EXYNOS || ARCH_MULTIPLATFORM || COMPILE_TEST)
 	select DRM_KMS_HELPER
 	select VIDEOMODE_HELPERS
 	select SND_SOC_HDMI_CODEC if SND_SOC
@@ -86,7 +86,7 @@ comment "Sub-drivers"
 
 config DRM_EXYNOS_G2D
 	bool "G2D"
-	depends on VIDEO_SAMSUNG_S5P_G2D=n
+	depends on VIDEO_SAMSUNG_S5P_G2D=n || COMPILE_TEST
 	select FRAME_VECTOR
 	help
 	  Choose this option if you want to use Exynos G2D for DRM.
@@ -114,7 +114,7 @@ config DRM_EXYNOS_SCALER
 
 config DRM_EXYNOS_GSC
 	bool "GScaler"
-	depends on VIDEO_SAMSUNG_EXYNOS_GSC=n
+	depends on VIDEO_SAMSUNG_EXYNOS_GSC=n || COMPILE_TEST
 	select DRM_EXYNOS_IPP
 	help
 	  Choose this option if you want to use Exynos GSC for DRM.

drivers/gpu/drm/exynos/exynos_drm_fbdev.c

@@ -10,6 +10,7 @@
 
 #include <linux/console.h>
 #include <linux/dma-mapping.h>
+#include <linux/vmalloc.h>
 
 #include <drm/drm_crtc.h>
 #include <drm/drm_fb_helper.h>