a20-som-paydia:fix uart3 pin configurations
a20-som-paydia:disable mmc0

Not used on paydia board.
a20-som-paydia:enable uart3 the scanner port
Revert "a20-som-paydia:disable mmc0"

This reverts commit 5eef67a11b0b58dc925e800b9d3bac20d1cce792.
mmc3_para: always on mode

Since a20-som-paydia board uses it as an "always on"
wifi port, not an sd card port.
Merge branch 'a20-som-paydia' of https://github.com/hunterhu/sunxi-boards into a20-som-kiosk-egtouch