ppc4xx: Add lcd4_lwmon5 support

This patch adds the fast booting LWMON5 derivat "lcd4_lwmon5".
Its a stripped down version of the full blown lwmon5 support,
without ECC, USB, POST and some other stuff. It used the newly
introduced SPL infrastrucure for SPL from NOR flash booting
on the PPC4xx.

By setting the environment variable "boot_os" to "yes", Linux
will be started from the SPL version. If not, the "normal"
U-Boot will be started.

Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/boards.cfg b/boards.cfg
index 31483d6..8b7933f 100644
--- a/boards.cfg
+++ b/boards.cfg
@@ -1010,6 +1010,7 @@
 korat                        powerpc     ppc4xx
 korat_perm                   powerpc     ppc4xx      korat               -              -           korat:KORAT_PERMANENT
 lwmon5                       powerpc     ppc4xx
+lcd4_lwmon5                  powerpc     ppc4xx      lwmon5              -              -           lwmon5:LCD4_LWMON5
 pcs440ep                     powerpc     ppc4xx
 quad100hd                    powerpc     ppc4xx
 sbc405                       powerpc     ppc4xx