drm/amdgpu: Remove CONFIG_DEBUG_FS guard around body of amdgpu_rap_debugfs_init()

After commit 8020f0f9

 ("drm/amd/amdgpu: enable W=1 for amdgpu"),
there is an instance of -Wunused-const-variable when CONFIG_DEBUG_FS is
disabled:

  drivers/gpu/drm/amd/amdgpu/amdgpu_rap.c:110:37: error: unused variable 'amdgpu_rap_debugfs_ops' [-Werror,-Wunused-const-variable]
    110 | static const struct file_operations amdgpu_rap_debugfs_ops = {
        |                                     ^
  1 error generated.

There is no reason for the body of this function to be guarded when
CONFIG_DEBUG_FS is disabled, as debugfs_create_file() is a stub that
just returns an error pointer in that situation. Remove the preprocessor
guards so that the variable never appears unused, while not changing
anything at run time.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>