Add support for ECDSA P-256 with SHA256

This adds a small EC library that is capable of verifying a signature of
SHA256 with ECDSA on the NIST P-256 curve.

Change-Id: I2a16639c92a77e8e4783c47ffbc56676de56eb59
(cherry picked from commit 3b2687399fe04ddf1655dcb2cf87e3c78b34034c)
update minui library call

The names of the res_create_* functions have changed.

Change-Id: I9990bb4f6e6dc2d7c62e2cb9e0831532c83b2bb9
(cherry picked from commit 89b9236061f98eb33d58345a691d3db6e032aaca)
charger: Query pathmap for recovery headers location

 * For compatibility with new recovery

Change-Id: I7054b662f41b2ff3360484f2b9e66efbfb6de09c
(cherry picked from commit 6d641d8ada75a22ba2cb3c36a3ab0653fbb6518e)