lib: Kconfig: fix help text for GZIP

commit 95f4bbd581cf ("lib: fdt: Allow LZO and GZIP DT compression in U-Boot")

introduced Kconfig option for gzip in U-Boot, but help text
says gzip for SPL, which is wrong. Fix this.

Signed-off-by: Heiko Schocher <hs@denx.de>
Acked-by: Marek Vasut <marex@denx.de>
diff --git a/lib/Kconfig b/lib/Kconfig
index 05f82d4..3801250 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -359,7 +359,7 @@
 	  This enables support for LZO compression algorithm.r
 
 config GZIP
-	bool "Enable gzip decompression support for SPL build"
+	bool "Enable gzip decompression support"
 	select ZLIB
 	default y
 	help