bootutil/crypto: Fix review comments on the ecdsa layer

Fixes in the ecdsa.h abstraction layer:
* Align indentation of parameters to the opening bracket of the function
* Remove inline in some of the bigger functions of the PSA Crypto abstraction
* Fix the prototype of ecdsa_verify for the PSA Crypto abstraction

Signed-off-by: Antonio de Angelis <Antonio.deAngelis@arm.com>
Change-Id: I28e1be83bc1a16fdf8b796f89c002528b1bd7791