acpi: Use finer-grained control of ACPI-table generation

Rather than keying everything off ACPIGEN, use the main
GENERATE_ACPI_TABLE option to determine whether the core ACPI code
is included. Make sure these option are not enabled in SPL/TPL since we
never generate tables there.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/Kconfig b/arch/Kconfig
index c5dd7fc..bea8ead 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -203,6 +203,7 @@
 	imply CMD_EXTENSION
 	imply KEYBOARD
 	imply PHYSMEM
+	imply GENERATE_ACPI_TABLE
 
 config SH
 	bool "SuperH architecture"