Convert CONFIG_SYS_MMC_ENV_DEV et al to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_MMC_ENV_DEV
   CONFIG_SYS_MMC_ENV_PART

Note that with this conversion we now have consistent behavior with
respect to ensuring that we have always selected the correct MMC
device and hardware partition.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/ls1046afrwy_tfa_defconfig b/configs/ls1046afrwy_tfa_defconfig
index 4251a7c..74863af 100644
--- a/configs/ls1046afrwy_tfa_defconfig
+++ b/configs/ls1046afrwy_tfa_defconfig
@@ -48,6 +48,7 @@
 CONFIG_PHY_VITESSE=y
 CONFIG_PHY_GIGE=y
 CONFIG_E1000=y
+CONFIG_FMAN_ENET=y
 CONFIG_PCI=y
 CONFIG_DM_PCI=y
 CONFIG_DM_PCI_COMPAT=y