kconfig: Move REGEX to Kconfig

Having this as a Kconfig allows it to be a dependent feature.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/dlvision-10g_defconfig b/configs/dlvision-10g_defconfig
index 1d2a571..2f508c3 100644
--- a/configs/dlvision-10g_defconfig
+++ b/configs/dlvision-10g_defconfig
@@ -1,3 +1,4 @@
 CONFIG_PPC=y
 CONFIG_4xx=y
 CONFIG_TARGET_DLVISION_10G=y
+CONFIG_REGEX=y