mtd/uclinux: Use generic __bss_stop instead of _ebss

The standard (see BSS_SECTION() in <asm-generic/vmlinux.lds.h> and
<asm-generic/sections.h>) symbol for the end of BSS is __bss_stop.
This allows to remove all local declarations that have been added to
several architectures just to please CONFIG_MTD_UCLINUX.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Michal Simek <monstr@monstr.eu>
Acked-by: Greg Ungerer <gerg@uclinux.org>

arch/sh/include/asm/sections.h

@@ -6,7 +6,6 @@
 extern long __nosave_begin, __nosave_end;
 extern long __machvec_start, __machvec_end;
 extern char __uncached_start, __uncached_end;
-extern char _ebss[];
 extern char __start_eh_frame[], __stop_eh_frame[];
 
 #endif /* __ASM_SH_SECTIONS_H */