libc/eglibc: fix installed scripts

Like rev 2002, eglibc installs some bash scripts, but use the path to the
buildtool bash as the interpreter (on the shebang line). This is only a
symlink to the real bash, and thus is not available at runtime.

Fix that by assuming that shell on the target *will* be /bin/bash.

Signed-off-by: Bryan Hundven <bryanhundven@gmail.com>
(transplanted from 6884dcb80121ebc8ce17deee62716ed75fc29393)

 # Super-H specific configuration file

 config ARCH_sh

     select ARCH_SUPPORTS_32

     select ARCH_DEFAULT_32

     select ARCH_USE_MMU

     select ARCH_SUPPORTS_BOTH_ENDIAN

     select ARCH_DEFAULT_LE

     help

       The Super-H architecture, as defined by:

         http://www.renesas.com/fmwk.jsp?cnt=superh_family_landing.jsp&fp=/products/mpumcu/superh_family/