Use lnr instead of "ln --relative" as systemd does
to avoid needing coreutils 8.16.

The patch is from systemd recipe and is rebased
so it can be applied for systemd-boot.

Signed-off-by: Jackie Huang <jackie.huang@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>

We apply the same setting in the existing gummiboot to
COMPATIBLE_HOST, so that it properly stops build for
unsupported architectures.

Signed-off-by: Jianxun Zhang <jianxun.zhang@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

The "systemd-boot" is gummiboot now included into systemd project.
The old gummiboot project supported in OE is dead.

Our intention is to get a gummiboot-like EFI bootloader without
much dependency on systemd and its features.

This work is largely derived from the existing bbclass and recipes
of gummiboot and systemd.
(commit tip: ee25d0e3987d7732a2e46e1640693b4cf419a9fc)

Please refer to the history up to the tip for authorship and
credit information for the original works.

To enable the systemd-boot in build, add this line
EFI_PROVIDER = "systemd-boot" in your machine conf file.

Signed-off-by: Jianxun Zhang <jianxun.zhang@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>