configs: am335x_boneblack: Enable fastboot flash capability

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Acked-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/am335x_boneblack_defconfig b/configs/am335x_boneblack_defconfig
index ed430e7..f45e409 100644
--- a/configs/am335x_boneblack_defconfig
+++ b/configs/am335x_boneblack_defconfig
@@ -17,6 +17,8 @@
 CONFIG_AUTOBOOT_DELAY_STR="d"
 CONFIG_AUTOBOOT_STOP_STR=" "
 CONFIG_FASTBOOT=y
+CONFIG_FASTBOOT_FLASH=y
+CONFIG_FASTBOOT_FLASH_MMC_DEV=1
 CONFIG_CMD_SPL=y
 # CONFIG_CMD_FLASH is not set
 # CONFIG_CMD_SETEXPR is not set