ARM: at91/dt: sama5: reduce the NFC command register map

commit 111573cc

 ("mtd: atmel_nand: check NFC busy flag by HSMC_SR
instead of NFC cmd regs")
check NFC busy by nfc SR instead of NFC cmd regs. So we don't need to
map NFC cmd registers to include NFCBUSY bit.
That means we only need map 0x08000000 instead of 0x10000000 for NFC
cmd regs.

This patch reduce the NFC cmd regs map for sama5d3 & sama5d4.

Signed-off-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>