spl: Convert spl_ymodem_load_image() to use linker list

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

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/common/spl/spl.c b/common/spl/spl.c
index 978df64..84ae003 100644
--- a/common/spl/spl.c
+++ b/common/spl/spl.c
@@ -384,10 +384,6 @@
 		return loader->load_image(&bootdev);
 
 	switch (boot_device) {
-#ifdef CONFIG_SPL_YMODEM_SUPPORT
-	case BOOT_DEVICE_UART:
-		return spl_ymodem_load_image(&bootdev);
-#endif
 #if defined(CONFIG_SPL_SPI_SUPPORT) || defined(CONFIG_SPL_SPI_FLASH_SUPPORT)
 	case BOOT_DEVICE_SPI:
 		return spl_spi_load_image(&bootdev);
diff --git a/common/spl/spl_ymodem.c b/common/spl/spl_ymodem.c
index d82b138..168b951 100644
--- a/common/spl/spl_ymodem.c
+++ b/common/spl/spl_ymodem.c
@@ -68,7 +68,7 @@
 	return size;
 }
 
-int spl_ymodem_load_image(struct spl_boot_device *bootdev)
+static int spl_ymodem_load_image(struct spl_boot_device *bootdev)
 {
 	int size = 0;
 	int err;
@@ -132,3 +132,4 @@
 	printf("Loaded %d bytes\n", size);
 	return 0;
 }
+SPL_LOAD_IMAGE_METHOD(0, BOOT_DEVICE_UART, spl_ymodem_load_image);
diff --git a/include/spl.h b/include/spl.h
index fd6ac01..7885521 100644
--- a/include/spl.h
+++ b/include/spl.h
@@ -181,9 +181,6 @@
 		.load_image = __method, \
 	}
 
-/* YMODEM SPL functions */
-int spl_ymodem_load_image(struct spl_boot_device *bootdev);
-
 /* SPI SPL functions */
 int spl_spi_load_image(struct spl_boot_device *bootdev);