spl: Convert spl_board_load_image() to use linker list

Add a linker list declaration for this method and remove the explicit
switch() code. Update existing users.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/mach-sunxi/board.c b/arch/arm/mach-sunxi/board.c
index 8a385a2..22f3e3c 100644
--- a/arch/arm/mach-sunxi/board.c
+++ b/arch/arm/mach-sunxi/board.c
@@ -133,13 +133,16 @@
 	return 0;
 }
 
-int spl_board_load_image(struct spl_boot_device *bootdev)
+#ifdef CONFIG_SPL_BUILD
+static int spl_board_load_image(struct spl_boot_device *bootdev)
 {
 	debug("Returning to FEL sp=%x, lr=%x\n", fel_stash.sp, fel_stash.lr);
 	return_to_fel(fel_stash.sp, fel_stash.lr);
 
 	return 0;
 }
+SPL_LOAD_IMAGE_METHOD(0, BOOT_DEVICE_BOARD, spl_board_load_image);
+#endif
 
 void s_init(void)
 {
diff --git a/arch/arm/mach-uniphier/boot-mode/spl_board.c b/arch/arm/mach-uniphier/boot-mode/spl_board.c
index 4eadc2f..e2b202e 100644
--- a/arch/arm/mach-uniphier/boot-mode/spl_board.c
+++ b/arch/arm/mach-uniphier/boot-mode/spl_board.c
@@ -65,7 +65,7 @@
 	return 0;
 }
 
-int spl_board_load_image(struct spl_boot_device *bootdev)
+static int spl_board_load_image(struct spl_boot_device *bootdev)
 {
 	int (*send_cmd)(u32 cmd, u32 arg);
 	int (*card_blockaddr)(u32 rca);
@@ -126,3 +126,4 @@
 
 	return 0;
 }
+SPL_LOAD_IMAGE_METHOD(0, BOOT_DEVICE_BOARD, spl_board_load_image);
diff --git a/arch/sandbox/cpu/spl.c b/arch/sandbox/cpu/spl.c
index 4cee293..2c45354 100644
--- a/arch/sandbox/cpu/spl.c
+++ b/arch/sandbox/cpu/spl.c
@@ -38,7 +38,7 @@
 	printf("%s\n", fname);
 }
 
-int spl_board_load_image(struct spl_boot_device *bootdev)
+static int spl_board_load_image(struct spl_boot_device *bootdev)
 {
 	char fname[256];
 	int ret;
@@ -50,6 +50,7 @@
 	/* Hopefully this will not return */
 	return os_spl_to_uboot(fname);
 }
+SPL_LOAD_IMAGE_METHOD(0, BOOT_DEVICE_BOARD, spl_board_load_image);
 
 void spl_board_init(void)
 {