drm/amdgpu: fix array out of bounds

When the initial value of i is greater than zero,
it may cause endless loop, resulting in array out
of bounds, fix it.

This is a port of the radeon fix to amdgpu.

Signed-off-by: tom will <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

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

···
 	if (pi->caps_stable_p_state) {
 		stable_p_state_sclk = (max_limits->sclk * 75) / 100;
 
-		for (i = table->count - 1; i >= 0; i++) {
+		for (i = table->count - 1; i >= 0; i--) {
 			if (stable_p_state_sclk >= table->entries[i].clk) {
 				stable_p_state_sclk = table->entries[i].clk;
 				break;