drm/amdgpu: Change type of module param `ppfeaturemask` to hexint

The newly added hexint helper is more convenient for bitmasks.

Before:

    $ more /sys/module/amdgpu/parameters/ppfeaturemask
    4294950911

After:

    $ more /sys/module/amdgpu/parameters/ppfeaturemask
    0xffffbfff

Cc: amd-gfx@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/374724/

drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c

@@ -391,12 +391,12 @@ MODULE_PARM_DESC(sched_hw_submission, "the max number of HW submissions (default
 module_param_named(sched_hw_submission, amdgpu_sched_hw_submission, int, 0444);
 
 /**
- * DOC: ppfeaturemask (uint)
+ * DOC: ppfeaturemask (hexint)
  * Override power features enabled. See enum PP_FEATURE_MASK in drivers/gpu/drm/amd/include/amd_shared.h.
  * The default is the current set of stable power features.
  */
 MODULE_PARM_DESC(ppfeaturemask, "all power features enabled (default))");
-module_param_named(ppfeaturemask, amdgpu_pp_feature_mask, uint, 0444);
+module_param_named(ppfeaturemask, amdgpu_pp_feature_mask, hexint, 0444);
 
 /**
  * DOC: forcelongtraining (uint)