drm/amdgpu: update fw_load_type module parameter doc to match code

amdgpu_ucode_get_load_type() does not interpret this parameter as
documented.  It is ignored for many ASIC types (which presumably
only support one load_type), and when not ignored it is only used
to force direct loading instead of PSP loading.  SMU loading is
only available for ASICs for which the parameter is ignored.

Signed-off-by: Yann Dirson <ydirson@free.fr>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -314,9 +314,12 @@ module_param_named(dpm, amdgpu_dpm, int, 0444);
 
 /**
  * DOC: fw_load_type (int)
- * Set different firmware loading type for debugging (0 = direct, 1 = SMU, 2 = PSP). The default is -1 (auto).
+ * Set different firmware loading type for debugging, if supported.
+ * Set to 0 to force direct loading if supported by the ASIC.  Set
+ * to -1 to select the default loading mode for the ASIC, as defined
+ * by the driver.  The default is -1 (auto).
  */
-MODULE_PARM_DESC(fw_load_type, "firmware loading type (0 = direct, 1 = SMU, 2 = PSP, -1 = auto)");
+MODULE_PARM_DESC(fw_load_type, "firmware loading type (0 = force direct if supported, -1 = auto)");
 module_param_named(fw_load_type, amdgpu_fw_load_type, int, 0444);
 
 /**