binutils: now depends on wchar

binutils starting at least from 2.23 when build for target require
uClibc configured with UCLIBC_HAS_WCHAR otherwise:

libtool: link: [...] -o as-new [...]
read.o: In function `read_symbol_name':
read.c:(.text+0x3634): undefined reference to `mbstowcs'
collect2: error: ld returned 1 exit status

because "mbstowcs" is not available in the C library.

Even though we're not yet using 2.23.2 as the default version, we will
probably do it in the near future, so this commit doesn't bother with
making the wchar dependency version-specific, and applies it to the
binutils package as a whole.

Fixes bug #6218

[Thomas:
 - more details in the commit log.
 - add comment about the wchar dependency
 - propagate the dependency to dropwatch (and fix a mistake in the
   architecture dependencies of the comment)
 - propagate the dependency to oprofile.]

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Anton Kolesov <akolesov@synopsys.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>