kernel.bbclass: use the consistent naming schema for initramfs
* use INITRAMFS_BASE_NAME and INITRAMFS_SYMLINK_NAME variables, like
other kernel artifacts are using
* use "${PKGE}-${PKGV}-${PKGR}-${MACHINE}-${DATETIME}" instead of
"${PV}-${PR}-${MACHINE}-${DATETIME}" to be consistent with other files
* allow to modify default symlink name with INITRAMFS_SYMLINK_NAME
instead of currently used:
initramfs_symlink_name=${type}-initramfs-${MACHINE}
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
