[U-Boot] [PATCH 1/5] env: allow undefined CONFIG_SYS_MMC_ENV_DEV

[Andre Przywara <andre.przywara@arm.com>]

So far we are required to always define the CONFIG_SYS_MMC_ENV_DEV
variable, even if a platform specific function overrides the weak
function that is using it.

Check for the existence of this Kconfig variable, eliminating the need
to define a dummy value.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
 env/mmc.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/env/mmc.c b/env/mmc.c
index c3cf35d01b..122fec3af8 100644
--- a/env/mmc.c
+++ b/env/mmc.c
@@ -124,7 +124,11 @@ __weak int mmc_get_env_addr(struct mmc *mmc, int copy, u32 *env_addr)
 
 __weak int mmc_get_env_dev(void)
 {
+#ifdef CONFIG_SYS_MMC_ENV_DEV
 	return CONFIG_SYS_MMC_ENV_DEV;
+#else
+	return 0;
+#endif
 }
 
 #ifdef CONFIG_SYS_MMC_ENV_PART
-- 
2.14.5