allwinner: doc: add missing paragraphs
allwinner: doc: add missing paragraphs

Add two empty lines to denote the paragraphs properly and improve
readability.

Reported-by: Samuel Holland <c16aab9fe3288df0fb8fc1d24990a300b6b8f299@sholland.org>
Signed-off-by: Andre Przywara <94eb15b8f54b8e37c3f8d338296201be47dc5c3e@arm.com>

achingupta/arm-trusted-firmware,achingupta/arm-trusted-firmware