meta: Add explict getVar param for (non) expansion

meta: Add explict getVar param for (non) expansion

Rather than just use d.getVar(X), use the more explict d.getVar(X, False)
since at some point in the future, having the default of expansion would
be nice. This is the first step towards that.

This patch was mostly made using the command:

sed -e 's:\(getVar([^,()]*\)\s*):\1, False):g' -i `grep -ril getVar *`

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