insane: Add SH4 musl mapping to the QA arch tests

insane: Add SH4 musl mapping to the QA arch tests

This change allows to pass QA for packages built with sh4-oe-linux-musl
toolchain, the problem is reproted while building core-image-minimal target:

  ERROR: readline-7.0-r0 do_package_qa:
  Error executing a python function in exec_python_func() autogenerated

(From OE-Core rev: dff25cb16ffca0876e5a747644bd6223129df402)

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>