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>
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index ff402dc..723288f 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -64,6 +64,6 @@
 
 endif
 
-ifneq ($(CONFIG_EFI_STUB)$(CONFIG_CMD_BOOTEFI_HELLO),)
+ifneq ($(CONFIG_EFI_STUB)$(CONFIG_CMD_BOOTEFI_HELLO_COMPILE),)
 extra-y += $(EFI_CRT0) $(EFI_RELOC)
 endif