net: Move CONFIG_SPL_NET_VCI_STRING into Kconfig

This patch also adds the SPL time VCI string into Kconfig.

Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/pcm051_rev3_defconfig b/configs/pcm051_rev3_defconfig
index eff099c..b277b3a 100644
--- a/configs/pcm051_rev3_defconfig
+++ b/configs/pcm051_rev3_defconfig
@@ -30,3 +30,4 @@
 CONFIG_USB_MUSB_GADGET=y
 CONFIG_USB_GADGET=y
 CONFIG_OF_LIBFDT=y
+CONFIG_SPL_NET_VCI_STRING="pcm051 U-Boot SPL"