rockchip: Add support to generate LZMA compressed U-boot binary

Add support for generating a LZMA-compressed U-boot binary with the
help of binman, if CONFIG_SPL_LZMA is selected.

Signed-off-by: Manoj Sai <abbaraju.manojsai@amarulasolutions.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>

arch/arm/dts/rockchip-u-boot.dtsi

@@ -58,6 +58,8 @@
 #endif
 #if defined(CONFIG_SPL_GZIP)
 					compression = "gzip";
+#elif defined(CONFIG_SPL_LZMA)
+					compression = "lzma";
 #else
 					compression = "none";
 #endif
@@ -66,6 +68,8 @@
 					u-boot-nodtb {
 #if defined(CONFIG_SPL_GZIP)
 					compress = "gzip";
+#elif defined(CONFIG_SPL_LZMA)
+					compress = "lzma";
 #endif
 					};
 #ifdef CONFIG_SPL_FIT_SIGNATURE