bfd: Re-enable 64-bit support for 32-bit Solaris targets

One of the recent Solaris patches removed want64=true from the 32-bit
Solaris targets.  This breaks GCC bootstrap: unlike Linux, GCC on
Solaris is always biarch, both in 32-bit-default and 64-bit-default
configurations, so the 64-bit multilib fails to build.

This patch undoes this incompatible change.

Tested on i386-pc-solaris2.11 and sparc-sun-solaris2.11.

2025-12-24  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

	bfd:
	* config.bfd <i[3-7]86-*-solaris2*> (want64): Add.
	<sparc-*-solaris2*>: Likewise.