libfdt: Make fdt_string() return a const pointer

Currently, fdt_string() returns a (non-const) char *, despite taking a
const void *fdt.  This is inconsistent with all the other read-only
functions which all return const pointers into the blob.

This patch fixes that.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2 files changed