dfu: samsung: move call to set_dfu_alt_info() to dfu common code

This common call can be used for setting proper entities based
on dfu command arguments.
The config: CONFIG_SET_DFU_ALT_INFO, was used only for few configs,
and now it is common.

The board file should implement:
- set_dfu_alt_info() function

Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com>
Tested-by: Lukasz Majewski <l.majewski@samsung.com>
[Test HW: Odroid U3 (Exynos 4412)]
diff --git a/drivers/dfu/dfu.c b/drivers/dfu/dfu.c
index ad0a7e7..0560afa 100644
--- a/drivers/dfu/dfu.c
+++ b/drivers/dfu/dfu.c
@@ -55,6 +55,9 @@
 	char *env_bkp;
 	int ret;
 
+#ifdef CONFIG_SET_DFU_ALT_INFO
+	set_dfu_alt_info(interface, devstr);
+#endif
 	str_env = getenv("dfu_alt_info");
 	if (!str_env) {
 		error("\"dfu_alt_info\" env variable not defined!\n");