efi_loader: Allow to compile helloworld.efi w/o bundling it

Today we can compile a self-contained hello world efi test binary that
allows us to quickly verify whether the EFI loader framwork works.

We can use that binary outside of the self-contained test case though,
by providing it to a to-be-tested system via tftp.

This patch separates compilation of the helloworld.efi file from
including it in the u-boot binary for "bootefi hello". It also modifies
the efi_loader test case to enable travis to pick up the compiled file.
Because we're now no longer bloating the resulting u-boot binary, we
can enable compilation always, giving us good travis test coverage.

Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Tom Rini <trini@konsulko.com>

test/py/tests/test_efi_loader.py

@@ -104,7 +104,7 @@ def test_efi_setup_static(u_boot_console):
     global net_set_up
     net_set_up = True
 
-@pytest.mark.buildconfigspec('cmd_bootefi_hello')
+@pytest.mark.buildconfigspec('cmd_bootefi_hello_compile')
 def test_efi_helloworld_net(u_boot_console):
     """Run the helloworld.efi binary via TFTP.