efi_loader: move HOST_ARCH to version_autogenerated.h

efi_default_filename.h requires HOST_ARCH to be defined. Up to now we
defined it via a CFLAGS. This does not scale. Add the symbol to
version_autogenerated.h instead.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
index fcb0af7..086521f 100644
--- a/lib/efi_loader/Makefile
+++ b/lib/efi_loader/Makefile
@@ -6,8 +6,7 @@
 # This file only gets included with CONFIG_EFI_LOADER set, so all
 # object inclusion implicitly depends on it
 
-asflags-y += -DHOST_ARCH="$(HOST_ARCH)" -I.
-ccflags-y += -DHOST_ARCH="$(HOST_ARCH)"
+asflags-y += -I.
 
 CFLAGS_efi_boottime.o += \
   -DFW_VERSION="0x$(VERSION)" \