spl: fit: Eanble GZIP support for image decompression

Add Kconfig option SPL_GZIP and SPL_ZLIB to enable gunzip support for
SPL boot, eg. falcon boot compressed kernel image.

Signed-off-by: York Sun <york.sun@nxp.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/lib/Makefile b/lib/Makefile
index 2eef1eb..da6a11a 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -11,7 +11,6 @@
 obj-$(CONFIG_EFI_LOADER) += efi_loader/
 obj-$(CONFIG_LZMA) += lzma/
 obj-$(CONFIG_LZO) += lzo/
-obj-$(CONFIG_ZLIB) += zlib/
 obj-$(CONFIG_BZIP2) += bzip2/
 obj-$(CONFIG_TIZEN) += tizen/
 obj-$(CONFIG_FIT) += libfdt/
@@ -26,7 +25,6 @@
 obj-$(CONFIG_ERRNO_STR) += errno_str.o
 obj-$(CONFIG_FIT) += fdtdec_common.o
 obj-$(CONFIG_TEST_FDTDEC) += fdtdec_test.o
-obj-$(CONFIG_GZIP) += gunzip.o
 obj-$(CONFIG_GZIP_COMPRESSED) += gzip.o
 obj-$(CONFIG_GENERATE_SMBIOS_TABLE) += smbios.o
 obj-y += initcall.o
@@ -49,6 +47,9 @@
 obj-$(CONFIG_SHA1) += sha1.o
 obj-$(CONFIG_SHA256) += sha256.o
 
+obj-$(CONFIG_$(SPL_)ZLIB) += zlib/
+obj-$(CONFIG_$(SPL_)GZIP) += gunzip.o
+
 obj-$(CONFIG_$(SPL_TPL_)SAVEENV) += qsort.o
 obj-$(CONFIG_$(SPL_TPL_)OF_LIBFDT) += libfdt/
 ifneq ($(CONFIG_$(SPL_TPL_)BUILD)$(CONFIG_$(SPL_TPL_)OF_PLATDATA),yy)