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

plat/allwinner/common/include/sunxi_private.h

@@ -12,7 +12,7 @@ void sunxi_configure_mmu_el3(int flags);
 void sunxi_cpu_on(u_register_t mpidr);
 void sunxi_cpu_off(u_register_t mpidr);
 void sunxi_disable_secondary_cpus(u_register_t primary_mpidr);
-void __dead2 sunxi_power_down(void);
+void sunxi_power_down(void);
 
 int sunxi_pmic_setup(uint16_t socid, const void *fdt);
 void sunxi_security_setup(void);

plat/allwinner/common/sunxi_pm.c

 /*
- * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -65,6 +65,11 @@ static void __dead2 sunxi_system_off(void)
 	sunxi_disable_secondary_cpus(read_mpidr());
 
 	sunxi_power_down();
+
+	udelay(1000);
+	ERROR("PSCI: Cannot turn off system, halting\n");
+	wfi();
+	panic();
 }
 
 static void __dead2 sunxi_system_reset(void)

plat/allwinner/sun50i_a64/sunxi_power.c

@@ -322,7 +322,7 @@ int sunxi_pmic_setup(uint16_t socid, const void *fdt)
 	return 0;
 }
 
-void __dead2 sunxi_power_down(void)
+void sunxi_power_down(void)
 {
 	switch (pmic) {
 	case GENERIC_H5:
@@ -368,8 +368,4 @@ void __dead2 sunxi_power_down(void)
 		break;
 	}
 
-	udelay(1000);
-	ERROR("PSCI: Cannot turn off system, halting.\n");
-	wfi();
-	panic();
 }

plat/allwinner/sun50i_h6/sunxi_power.c

@@ -95,7 +95,7 @@ int sunxi_pmic_setup(uint16_t socid, const void *fdt)
 	return 0;
 }
 
-void __dead2 sunxi_power_down(void)
+void sunxi_power_down(void)
 {
 	uint8_t val;
 
@@ -111,9 +111,4 @@ void __dead2 sunxi_power_down(void)
 	default:
 		break;
 	}
-
-	udelay(1000);
-	ERROR("PSCI: Cannot communicate with PMIC, halting\n");
-	wfi();
-	panic();
 }