PKGFILE: version is now completely constructed from git

`pkgver` and `pkgrel` now hard coded to 1. The PKGFILE will getting
changed on a `makepkg`-run.

To prevent some version crashes no commit with changes to `pkgver` and
`pkgrel` should be accepted.

Signed-off-by: Silvio Fricke <silvio.fricke@gmail.com>

PKGBUILD

@@ -1,6 +1,6 @@
 pkgname=dracut-git
-pkgver=$(date +%s)
+pkgver=1
-pkgrel=$(git log --pretty=format:%h |head -n 1)
+pkgrel=1
 pkgdesc="Initramfs generation utility"
 arch=('i686' 'x86_64')
 url="https://dracut.wiki.kernel.org/"
@@ -14,6 +14,12 @@ backup=(etc/dracut.conf)
 source=()
 md5sums=()
 
+pkgver() {
+  cd ..
+  desc="$(git describe)"
+  printf "%s.%s.%s" ${desc//-/ }
+}
+
 build() {
   cd ..
   make sysconfdir=/etc || return 1