ARM: dts: dove: Fix uart[23] reg property

Fix Dove's register addresses of uart2 and uart3 nodes that seem to
be broken since ages due to a copy-and-paste error.

Cc: <stable@vger.kernel.org> # 3.7+
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>