ARM: dts: spear1340: Update serial node properties

Reorder dma and dma-names property for serial node to make it compliant
with bindings.

Fixes: 6e8887f6

 ("ARM: SPEAr13xx: Pass generic DW DMAC platform data from DT")
Signed-off-by: Kuldeep Singh <singh.kuldeep87k@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/20220326042313.97862-3-singh.kuldeep87k@gmail.com'
Signed-off-by: Arnd Bergmann <arnd@arndb.de>