meta/scripts: Various getVar/getVarFlag expansion parameter fixes

meta/scripts: Various getVar/getVarFlag expansion parameter fixes

There were a few straggling expansion parameter removals left for
getVar/getVarFlag where the odd whitespace meant they were missed
on previous passes. There were also some plain broken ussages such
as:

d.getVar('ALTERNATIVE_TARGET', old_name, True)
path = d.getVar('PATH', d, True)
d.getVar('IMAGE_ROOTFS', 'True')

which I've corrected (they happend to work by luck).

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>