Historically we used mysys_ssl for SSL-related code, built with
special compiler options and flags.  This is no longer the case, and
the separate directory and library no longer serves any purpose.  Move
source files into the mysys directory, and include them in the 'mysys'
library.

Change-Id: I37e1fd1dee26f6d5b5700303507f82bb976252f5
(cherry picked from commit bef9aba16bc2b4a8ac78c1bba7244e40ecb23cec)