common: Move bootm_decomp_image() to image.c (as image_decomp())

Upcoming patches want to add decompression to use cases that are no
longer directly related to booting. It makes sense to retain a single
decompression routine, but it should no longer be in bootm.c (which is
not compiled for all configurations). This patch moves
bootm_decomp_image() to image.c and renames it to image_decomp() in
preparation of those upcoming patches.

Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
[trini: Fix warning around handle_decomp_error being unused]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/test/compression.c b/test/compression.c
index 7bc0f73..dc5e946 100644
--- a/test/compression.c
+++ b/test/compression.c
@@ -471,15 +471,15 @@
 	unc_len = strlen(plain);
 	compress(uts, (void *)plain, unc_len, compress_buff, compress_size,
 		 &compress_size);
-	err = bootm_decomp_image(comp_type, load_addr, image_start,
-				 IH_TYPE_KERNEL, map_sysmem(load_addr, 0),
-				 compress_buff, compress_size, unc_len,
-				 &load_end);
+	err = image_decomp(comp_type, load_addr, image_start,
+			   IH_TYPE_KERNEL, map_sysmem(load_addr, 0),
+			   compress_buff, compress_size, unc_len,
+			   &load_end);
 	ut_assertok(err);
-	err = bootm_decomp_image(comp_type, load_addr, image_start,
-				 IH_TYPE_KERNEL, map_sysmem(load_addr, 0),
-				 compress_buff, compress_size, unc_len - 1,
-				 &load_end);
+	err = image_decomp(comp_type, load_addr, image_start,
+			   IH_TYPE_KERNEL, map_sysmem(load_addr, 0),
+			   compress_buff, compress_size, unc_len - 1,
+			   &load_end);
 	ut_assert(err);
 
 	/* We can't detect corruption when not decompressing */
@@ -487,10 +487,10 @@
 		return 0;
 	memset(compress_buff + compress_size / 2, '\x49',
 	       compress_size / 2);
-	err = bootm_decomp_image(comp_type, load_addr, image_start,
-				 IH_TYPE_KERNEL, map_sysmem(load_addr, 0),
-				 compress_buff, compress_size, 0x10000,
-				 &load_end);
+	err = image_decomp(comp_type, load_addr, image_start,
+			   IH_TYPE_KERNEL, map_sysmem(load_addr, 0),
+			   compress_buff, compress_size, 0x10000,
+			   &load_end);
 	ut_assert(err);
 
 	return 0;