contrib: fix gcc test suite on system without echo -e

Fix the use of quotes in contrib/gcc-test-suite/Makefile to solve the
problem where board.exp is incorrectly generated on some build systems
where 'echo -e' is not handled correctly.

Signed-off-by: Andy Gibbs <andyg1001@hotmail.co.uk>
[Yann E. MORIN: fix space damage, pretty-up the stuff]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

 # 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/