Convert CONFIG_BITBANGMII_MULTI to Kconfig

This converts the following to Kconfig:
   CONFIG_BITBANGMII_MULTI

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/armadillo-800eva_defconfig b/configs/armadillo-800eva_defconfig
index 2f5c115..4f00b20 100644
--- a/configs/armadillo-800eva_defconfig
+++ b/configs/armadillo-800eva_defconfig
@@ -41,6 +41,7 @@
 CONFIG_VERSION_VARIABLE=y
 # CONFIG_MMC is not set
 CONFIG_BITBANGMII=y
+CONFIG_BITBANGMII_MULTI=y
 CONFIG_PHY_SMSC=y
 CONFIG_SH_ETHER=y
 CONFIG_SCIF_CONSOLE=y