* config.gcc (sparc-*-elf): Include sparc/sol2.h.
(sparc-*-rtems*): Include sparc/sol2.h and sparc/elf.h.
(sparclite-*-elf*, sparc86x-*-elf*): Likewise.
* config/sparc/elf.h: No longer include sol2.h.
* config/sparc/lifeelf.h: No longer include sparc/elf.h.
* config/sparc/rtemself.h, config/sparc/sp86x-elf.h: Likewise.