x86: Tidy up use of CONFIG_ACPIGEN

This is enabled for quite a few boards which don't create ACPI tables.
Tidy this up by dropping the option for some boards.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/Kconfig b/arch/Kconfig
index c9608cd..c5dd7fc 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -257,7 +257,7 @@
 	imply PCH
 	imply PHYSMEM
 	imply RTC_MC146818
-	imply ACPIGEN if !QEMU
+	imply ACPIGEN if !QEMU && !EFI_APP
 	imply SYSINFO if GENERATE_SMBIOS_TABLE
 	imply SYSINFO_SMBIOS if GENERATE_SMBIOS_TABLE
 	imply TIMESTAMP