[KERNEL] Rename recipe for Linux kernel 4.4

This is done to fix a temporary limitation in using the SRVREV file (external to this layer) where the git repositoris'sha1 are fixed. In this file can't be present two recipes with the same name and different revision (in this case linux-seco-rk 4.4 and 4.19). So we rename the kernel which is going to be deprecated.