allwinner: Merge duplicate code in sunxi_power_down

The action of last resort isn't going to change between SoCs. This moves
that code back to the PSCI implementation, where it more obviously
matches the code in sunxi_system_reset().

The two error messages say essentially the same thing anyway.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Change-Id: I62ac35fdb5ed78a016e9b18281416f1dcea38a4a
diff --git a/plat/allwinner/sun50i_h6/sunxi_power.c b/plat/allwinner/sun50i_h6/sunxi_power.c
index 08c74f8..7bb266b 100644
--- a/plat/allwinner/sun50i_h6/sunxi_power.c
+++ b/plat/allwinner/sun50i_h6/sunxi_power.c
@@ -95,7 +95,7 @@
 	return 0;
 }
 
-void __dead2 sunxi_power_down(void)
+void sunxi_power_down(void)
 {
 	uint8_t val;
 
@@ -111,9 +111,4 @@
 	default:
 		break;
 	}
-
-	udelay(1000);
-	ERROR("PSCI: Cannot communicate with PMIC, halting\n");
-	wfi();
-	panic();
 }