riscv: delay initialization of caches and debug UART

Move the initialization of the caches and the debug UART until after
board_init_f_init_reserve. This is in preparation for SMP support, where
code prior to this point will be executed by all harts. This ensures
that initialization will only be performed once on the main hart running
U-Boot.

Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/riscv/cpu/start.S b/arch/riscv/cpu/start.S
index 81ea52b..a30f6f7 100644
--- a/arch/riscv/cpu/start.S
+++ b/arch/riscv/cpu/start.S
@@ -45,10 +45,6 @@
 	/* mask all interrupts */
 	csrw	MODE_PREFIX(ie), zero
 
-	/* Enable cache */
-	jal	icache_enable
-	jal	dcache_enable
-
 /*
  * Set stackpointer in internal/ex RAM to call board_init_f
  */
@@ -57,10 +53,6 @@
 	li	t1, CONFIG_SYS_INIT_SP_ADDR
 	and	sp, t1, t0		/* force 16 byte alignment */
 
-#ifdef CONFIG_DEBUG_UART
-	jal	debug_uart_init
-#endif
-
 call_board_init_f_0:
 	mv	a0, sp
 	jal	board_init_f_alloc_reserve
@@ -74,6 +66,14 @@
 	/* save the boot hart id to global_data */
 	SREG	s0, GD_BOOT_HART(gp)
 
+	/* Enable cache */
+	jal	icache_enable
+	jal	dcache_enable
+
+#ifdef CONFIG_DEBUG_UART
+	jal	debug_uart_init
+#endif
+
 	mv	a0, zero		/* a0 <-- boot_flags = 0 */
 	la	t5, board_init_f
 	jr	t5			/* jump to board_init_f() */