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/lib/Makefile b/lib/Makefile
index 7950e84..bde046c 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -58,7 +58,7 @@
 obj-$(CONFIG_TPM_V2) += tpm-v2.o
 endif
 
-obj-$(CONFIG_$(SPL_)ACPIGEN) += acpi/
+obj-$(CONFIG_$(SPL_TPL_)GENERATE_ACPI_TABLE) += acpi/
 obj-$(CONFIG_$(SPL_)MD5) += md5.o
 obj-$(CONFIG_ECDSA) += ecdsa/
 obj-$(CONFIG_$(SPL_)RSA) += rsa/