Bugfix
   * Fix build errors when the only enabled elliptic curves are Montgomery
     curves. Raised by signpainter in #941 and by Taiki-San in #1412. This
     also fixes missing declarations reported by Steven Cooreman in #1147.
   * Fix self-test failure when the only enabled short Weierstrass elliptic
     curve is secp192k1. Fixes #2017.

Add ChangeLog entry for single-curve build fixes
Add ChangeLog entry for single-curve build fixes

Fix #941, #1412, #1147, #2017

Signed-off-by: Gilles Peskine <f829db02715a0ea34b7c8e25097dae9e3517e831@arm.com>
