CRAMFS: support cramfs in RAM

cramfsls and cramfsload are added to the command list.
A cramfs placed at 'cramfs_addr' can the be listed with 'cramfsls' and files
can be loaded with 'cramfsload'. 'cramfs_addr' is an environment variable
specifying the address the cramfs is located.
This works for powerpc and for ARM.

Use CONFIG_CMD_CRAMFS.

Signed-off-by: Andreas Huber <andreas.huber@keymile.com>
Signed-off-by: Heiko Schocher <hs@denx.de>
diff --git a/common/Makefile b/common/Makefile
index 13b3298..dbf7a05 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -105,6 +105,7 @@
 COBJS-$(CONFIG_CMD_IRQ) += cmd_irq.o
 COBJS-$(CONFIG_CMD_ITEST) += cmd_itest.o
 COBJS-$(CONFIG_CMD_JFFS2) += cmd_jffs2.o
+COBJS-$(CONFIG_CMD_CRAMFS) += cmd_cramfs.o
 COBJS-$(CONFIG_CMD_LICENSE) += cmd_license.o
 COBJS-y += cmd_load.o
 COBJS-$(CONFIG_LOGBUFFER) += cmd_log.o