Refactor the code using the pk11 ECC constants.

Refactor the code using the pk11 ECC constants.

The pk11/constants.h header contained static CK_BYTE arrays and
we had to use #defines to pull only those we need.  This commit
changes the constants to only define byte arrays with the content
and either use them directly or define the CK_BYTE arrays locally
where used.

(cherry picked from commit da38bd0e1d9739990fcbd582369698e81968ca62)