Readd EC_GROUP_get_curve_GFp.

wpa_supplicant needs this in order to get the order of the coordinate
field, apparently so that they can hash to a point.

Change-Id: I92d5df7b37b67ace5f497c25f53f16bbe134aced
Reviewed-on: https://boringssl-review.googlesource.com/1622
Reviewed-by: Adam Langley <agl@google.com>
3 files changed