Update gitignore

Add all the .in files handled in the Makefile, drop never present binary
objects and adjust the to look at dist folder in the top directory.

Bits like temporary editor files - *~  *.swp or others - should be
handled by the end-user. There're dozen of editors and naming schemes
out there and adding all the variations to every project does not scale.

See `man gitignore` how to set local excludes.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>

.gitignore

@@ -1,4 +1,7 @@
-dist/*
-*.o
+/dist
 dkms
 dkms.8
+dkms_autoinstaller
+dkms.service
+kernel_install.d_dkms
+kernel_postinst.d_dkms