scripts/bitbake: Check the git-native version and build it if necessary

scripts/bitbake: Check the git-native version and build it if necessary

We require git version 1.7.5 or later for the git remote --mirror=xxx syntax.
If we have an older version of git, this patch ensure we build git-replacement-native.
We add an alternative PROVIDES in the same way as tar-native to allow this script
to trigger the build whilst still allowing git-native in ASSUME_PROVIDED.

(From OE-Core rev: 269f3b3cfacaf229d5e45177ee01b16561370ee3)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>