Revert "octeon: mark source-only"

The memory leak is fixed by the kernel patches backported in the
previous commit.

This reverts commit 1fa8780.

Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>

target/linux/octeon/Makefile

@@ -7,7 +7,7 @@ include $(TOPDIR)/rules.mk
 ARCH:=mips64
 BOARD:=octeon
 BOARDNAME:=Cavium Networks Octeon
-FEATURES:=squashfs ramdisk pci source-only usb
+FEATURES:=squashfs ramdisk pci usb
 CPU_TYPE:=octeonplus
 
 KERNEL_PATCHVER:=5.10