buildroot

python-pylibftdi: use package name for .mk file

Found using [1]:
check-package --include-only TypoInPackageVariable $(find * -type f)
and manually fixed.

[1] http://patchwork.ozlabs.org/patch/729672/

Signed-off-by: Ricardo Martincoski <ricardo.martincoski@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>