am335x_evm: Enable CONFIG_SPL_ENV_SUPPORT on EMMC_BOOT

When we're using EMMC_BOOT that means we have environment on eMMC so
we can make use of CONFIG_SPL_ENV_SUPPORT within Falcon Mode.

Signed-off-by: Tom Rini <trini@ti.com>
diff --git a/include/configs/am335x_evm.h b/include/configs/am335x_evm.h
index 0205b87..9d60a4d 100644
--- a/include/configs/am335x_evm.h
+++ b/include/configs/am335x_evm.h
@@ -394,6 +394,7 @@
 #elif defined(CONFIG_EMMC_BOOT)
 #undef CONFIG_ENV_IS_NOWHERE
 #define CONFIG_ENV_IS_IN_MMC
+#define CONFIG_SPL_ENV_SUPPORT
 #define CONFIG_SYS_MMC_ENV_DEV		1
 #define CONFIG_SYS_MMC_ENV_PART		2
 #define CONFIG_ENV_OFFSET		0x0