make: configure host-make with host- prefix

Fixes:
http://autobuild.buildroot.net/results/e29/e293aadc692d2ed337881ef2172ddf66a60bc05c/



And many more.

Install as 'host-make' rather than just 'make', as that otherwise confuses a
number of packages when they invoke recursive / sub-make.  The internal job
control logic of GNU make is version dependant, so mixing versions may lead
to issues like:

make[1]: Entering directory `/home/peko/autobuild/instance-0/output/build/boa-0.94.14rc21'
(cd src && make -w --jobserver-fds=5,6 -j)
make: unrecognized option '--jobserver-fds=5,6'

With this rename, only packages explicitly opting in for our host-make
(using the BR2_MAKE / BR2_MAKE_HOST_DEPENDENCY logic) will use it.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>