Revert abbreviation of month name
Revert abbreviation of month name

Commit 6a00ff2f, "Extract document version from git tag" changed the
date annotation from full month to the abbreviation. Full month looks
better on the title page, so revert that hunk of the change.

Signed-off-by: Grant Likely <9069e6f5a2b566e2674a0ba1e2bf39c12c195fad@arm.com>

devicetree-org/devicetree-specification