Revert "powerpc: ppc4xx: remove lwmon5 support"

This reverts commit 8fe11b8901a31d11990488c82bc23612589d57be.

I'll add support to lwmon5 in the next patch and will remove
support for the broken lcd4_lwmon5 as well.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/board/lwmon5/Kconfig b/board/lwmon5/Kconfig
new file mode 100644
index 0000000..90566d8
--- /dev/null
+++ b/board/lwmon5/Kconfig
@@ -0,0 +1,9 @@
+if TARGET_LWMON5
+
+config SYS_BOARD
+	default "lwmon5"
+
+config SYS_CONFIG_NAME
+	default "lwmon5"
+
+endif