complibs/isl: add HTTP mirror

Add well-known HTTP mirror as a fallback. This lets crosstool-ng
work when behind a HTTP/HTTPS only proxy.

Signed-off-by: Michael Hope <michaelh@juju.net.nz>
[me: split original patch in two]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Message-Id: <aeb4a850d0786ee62dc2.1375559989@wanda>
Patchwork-Id: 264436

# 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/