libv4l: add patches to fix musl build issues, and enable on musl

This commit adds two patches to the libv4l package, the first one
fixes the __off_t usage and the second one fixes locale-related
function usage. Those two patches allow libv4l to build fine against
musl, so we remove the dependency of glibc || uclibc.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>