efi: x86: Correct the condition for installing ACPI tables

It is not always the case that U-Boot builds the ACPI tables itself. For
example, when booting from coreboot, the ACPI tables are built by
coreboot.

Correct the Makefile condition so that U-Boot can pass on tables built
by a previous firmware stage.

Tidy up the installation-condition code while we are here.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
index 1a8c8d7..0eb748f 100644
--- a/lib/efi_loader/Makefile
+++ b/lib/efi_loader/Makefile
@@ -78,7 +78,7 @@
 obj-$(CONFIG_VIDEO) += efi_gop.o
 obj-$(CONFIG_BLK) += efi_disk.o
 obj-$(CONFIG_NETDEVICES) += efi_net.o
-obj-$(CONFIG_GENERATE_ACPI_TABLE) += efi_acpi.o
+obj-$(CONFIG_ACPI) += efi_acpi.o
 obj-$(CONFIG_GENERATE_SMBIOS_TABLE) += efi_smbios.o
 obj-$(CONFIG_EFI_RNG_PROTOCOL) += efi_rng.o
 obj-$(CONFIG_EFI_TCG2_PROTOCOL) += efi_tcg2.o