fs/squashfs: add filesystem commands

Add 'ls' and 'load' commands.

Signed-off-by: Joao Marcos Costa <joaomarcos.costa@bootlin.com>
diff --git a/cmd/Makefile b/cmd/Makefile
index 7075037..ef2a22f 100644
--- a/cmd/Makefile
+++ b/cmd/Makefile
@@ -63,6 +63,7 @@
 obj-$(CONFIG_CMD_EXT2) += ext2.o
 obj-$(CONFIG_CMD_FAT) += fat.o
 obj-$(CONFIG_CMD_FDT) += fdt.o
+obj-$(CONFIG_CMD_SQUASHFS) += sqfs.o
 obj-$(CONFIG_CMD_FLASH) += flash.o
 obj-$(CONFIG_CMD_FPGA) += fpga.o
 obj-$(CONFIG_CMD_FPGAD) += fpgad.o