drm/amd/display: not reset dmub in driver.

[Why]
during S0i3, set power state is toggled a few times,
and dmub uC will restart with current reset/hw_init.

[How]
Remove reset in set power state, and before doing hw_init,
check if dmub is enabled, and doing FW autoload check only
if dmub is already enabled.
Signed-off-by: Yongqiang Sun <yongqiang.sun@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dmub/src/dmub_dcn20.c

@@ -275,7 +275,11 @@ void dmub_dcn20_set_inbox1_wptr(struct dmub_srv *dmub, uint32_t wptr_offset)
 
 bool dmub_dcn20_is_hw_init(struct dmub_srv *dmub)
 {
-	return REG_READ(DMCUB_REGION3_CW2_BASE_ADDRESS) != 0;
+	uint32_t is_hw_init;
+
+	REG_GET(DMCUB_CNTL, DMCUB_ENABLE, &is_hw_init);
+
+	return is_hw_init != 0;
 }
 
 bool dmub_dcn20_is_supported(struct dmub_srv *dmub)