docs: --target versus --host

In the very beginnings, eons ago, autotools also got confused by this
whole build vs. host vs. target, and got it wrong. Now they fixed it,
but they want to keep backward compatibility, so the --target is still
recongised, although ./configure will complain if you do so. It is
better to use --host.

Signed-off-by: "Trevor Woerner" <twoerner@gmail.com>
[yann.morin.1998@anciens.enib.fr: add build/host clarification]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

 # Super-H specific configuration file

 ## 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:

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