Configurations/10-main.conf: clean up HP-UX targets and add magic macros.

HP-UX provides sockets symbols with incompatible prototypes under same
name. This caused problems in 64-bit builds. Additional macros force
unambiguous symbols with unambiguous prototypes.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5742)