drm/amd/powerplay: return false instead of -EINVAL

Returning -EINVAL from a bool-returning function
phm_check_smc_update_required_for_display_configuration has an unexpected
effect of returning true, which is probably not what was intended.
Replace -EINVAL by false.

The only place this function is called from is
psm_adjust_power_state_dynamic in
drivers/gpu/drm/amd/powerplay/eventmgr/psm.c:106:

	if (!equal || phm_check_smc_update_required_for_display_configuration(hwmgr)) {
		phm_apply_state_adjust_rules(hwmgr, requested, pcurrent);
		phm_set_power_state(hwmgr, &pcurrent->hardware, &requested->hardware);
		hwmgr->current_ps = requested;
	}

It seems to expect a boolean value here.

This issue has been found using the following Coccinelle semantic patch
written by Peter Senna Tschudin:
<smpl>
@@
identifier f;
constant C;
typedef bool;
@@
bool f (...){
<+...
* return -C;
...+>
}
</smpl>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Andrew Shadura <andrew.shadura@collabora.co.uk>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/powerplay/hwmgr/hardwaremanager.c

@@ -272,7 +272,7 @@ bool phm_check_smc_update_required_for_display_configuration(struct pp_hwmgr *hw
 	PHM_FUNC_CHECK(hwmgr);
 
 	if (hwmgr->hwmgr_func->check_smc_update_required_for_display_configuration == NULL)
-		return -EINVAL;
+		return false;
 
 	return hwmgr->hwmgr_func->check_smc_update_required_for_display_configuration(hwmgr);
 }