x86: Support zboot and bootm in the EFI app

These have been disabled due to the rudimentary support available. It is
a little better now, so enable these options.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/configs/efi-x86_app64_defconfig b/configs/efi-x86_app64_defconfig
index f1cf43c..0fc358d 100644
--- a/configs/efi-x86_app64_defconfig
+++ b/configs/efi-x86_app64_defconfig
@@ -20,7 +20,7 @@
 CONFIG_LAST_STAGE_INIT=y
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PBSIZE=532
-# CONFIG_CMD_BOOTM is not set
+CONFIG_CMD_BOOTZ=y
 CONFIG_CMD_PART=y
 # CONFIG_CMD_NET is not set
 CONFIG_CMD_CACHE=y