drm/xe: don't build debugfs files when CONFIG_DEBUG_FS=n

If we unconditionally build the debugfs files, we'll get both the static
inline stubs from the headers and the real functions for
CONFIG_DEBUG_FS=n. Avoid building the debugfs files with that config.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Closes: https://lore.kernel.org/r/152521f9-119f-4c61-b467-3e91f4aecb1a@infradead.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240124090515.3363901-1-jani.nikula@intel.com

drivers/gpu/drm/xe/Makefile

@@ -222,8 +222,6 @@ xe-$(CONFIG_DRM_XE_DISPLAY) += \
 	i915-display/intel_ddi.o \
 	i915-display/intel_ddi_buf_trans.o \
 	i915-display/intel_display.o \
-	i915-display/intel_display_debugfs.o \
-	i915-display/intel_display_debugfs_params.o \
 	i915-display/intel_display_device.o \
 	i915-display/intel_display_driver.o \
 	i915-display/intel_display_irq.o \
@@ -267,7 +265,6 @@ xe-$(CONFIG_DRM_XE_DISPLAY) += \
 	i915-display/intel_modeset_setup.o \
 	i915-display/intel_modeset_verify.o \
 	i915-display/intel_panel.o \
-	i915-display/intel_pipe_crc.o \
 	i915-display/intel_pmdemand.o \
 	i915-display/intel_pps.o \
 	i915-display/intel_psr.o \
@@ -294,6 +291,13 @@ ifeq ($(CONFIG_DRM_FBDEV_EMULATION),y)
 	xe-$(CONFIG_DRM_XE_DISPLAY) += i915-display/intel_fbdev.o
 endif
 
+ifeq ($(CONFIG_DEBUG_FS),y)
+	xe-$(CONFIG_DRM_XE_DISPLAY) += \
+		i915-display/intel_display_debugfs.o \
+		i915-display/intel_display_debugfs_params.o \
+		i915-display/intel_pipe_crc.o
+endif
+
 obj-$(CONFIG_DRM_XE) += xe.o
 obj-$(CONFIG_DRM_XE_KUNIT_TEST) += tests/