Rename overlay manager to software cache

bfd/
	* reloc.c (BFD_RELOC_EPIPHANY_OVERHIGH): Rename to ...
	(BFD_RELOC_EPIPHANY_CACHEHIGH): ... this.
	(BFD_RELOC_EPIPHANY_OVERLOW): Rename to ...
	(BFD_RELOC_EPIPHANY_CACHELOW): ... this.
	(BFD_RELOC_EPIPHANY_OVER32): Rename to ...
	(BFD_RELOC_EPIPHANY_CACHE32): ... this.
	* libbfd.h: Regenerate.
	* bfd-in2.h: Regenerate.
	* elf32-epiphany.c: Rename overlaymanager to cachemanager.
	(epiphany_elf_howto_table): Rename R_EPIPHANY_OVERHIGH to
	R_EPIPHANY_CACHEHIGH.  Rename R_EPIPHANY_OVERLOW to R_EPIPHANY_CACHELOW.
	Rename R_EPIPHANY_OVER32 to R_EPIPHANY_CACHE32.
	(epiphany_reloc_type_lookup): Likewise.
	(epiphany_final_link_relocate): Likewise.
	(epiphany_elf_finish_dynamic_sections): Rename .overlayman section to .cacheman.

cpu/
	* epiphany.cpu (parse_imm16): Rename BFD_RELOC_EPIPHANY_OVERHIGH
	to BFD_RELOC_EPIPHANY_CACHEHIGH and BFD_RELOC_EPIPHANY_OVERLOW to
	BFD_RELOC_EPIPHANY_CACHELOW.

gas/
	* config/tc-epiphany.h: Rename R_EPIPHANY_OVER32 to
	BFD_RELOC_EPIPHANY_CACHE32.
	* config/tc-epiphany.c (epiphany_parse_cons_expression): Rename
	BFD_RELOC_EPIPHANY_OVER32 to BFD_RELOC_EPIPHANY_CACHE32.
	(epiphany_cons_fix_new): Likewise.
	(epiphany_fix_adjustable): Rename BFD_RELOC_EPIPHANY_OVERHIGH to
	BFD_RELOC_EPIPHANY_CACHEHIGH and BFD_RELOC_EPIPHANY_OVERLOW to
	BFD_RELOC_EPIPHANY_CACHELOW.
	(epiphany_cgen_parse_fix_exp): Likewise.

include/
	* elf/epiphany.h (R_EPIPHANY_OVERHIGH): Rename to ...
	(R_EPIPHANY_CACHEHIGH): ... this.
	(R_EPIPHANY_OVERLOW): Rename to ...
	(R_EPIPHANY_CACHELOW): ... this.
	(R_EPIPHANY_OVER32): Rename to ...
	(R_EPIPHANY_CACHE32): ... this.

opcodes/
	* epiphany-asm.c: Regenerated.