Add tools helper reporting blkid support.

src/cryptsetup.h

@@ -120,6 +120,7 @@ int tools_detect_signatures(const char *device, tools_probe_filter_info filter,
 int tools_wipe_all_signatures(const char *path);
 int tools_superblock_block_size(const char *device, char *sb_name,
 				size_t sb_name_len, unsigned *r_block_size);
+bool tools_blkid_supported(void);
 
 int tools_lookup_crypt_device(struct crypt_device *cd, const char *type,
 		const char *data_device_path, char **r_name);

src/utils_blockdev.c

@@ -371,3 +371,8 @@ int tools_superblock_block_size(const char *device, char *sb_name, size_t sb_nam
 
 	return r;
 }
+
+bool tools_blkid_supported(void)
+{
+	return blk_supported() != 0;
+}