scripts/dtc: Update to upstream version v1.4.0

Update to the latest version of dtc with the following notable
enhancements and bug fixes:

* fdtput: expand fdt if value does not fit
* dtc/fdt{get, put}/convert-dtsv0-lexer: convert to new usage helpers
* libfdt: Add fdt_next_subnode() to permit easy subnode iteration
* utilfdt_read: pass back up the length of data read
* util_version: new helper for displaying version info
* die: constify format string arg
* utilfdt_read_err: use xmalloc funcs
* Export fdt_stringlist_contains()
* dtc: Drop the '-S is deprecated' warning
* dtc/libfdt: sparse fixes
* dtc/libfdt: introduce fdt types for annotation by endian checkers
* Fix util_is_printable_string
* dtc: srcpos_verror() should print to stderr
* libfdt: Added missing functions to shared library

Shipped bison/flex generated files were built on an Ubuntu 13.10 system.

Signed-off-by: Grant Likely <grant.likely@linaro.org>