ARM: dts: at91: sama7g5ek: move eeproms to flexcom8

The rev4 of the board sama7g5ek has the eeproms on flexcom8 instead of
flexcom1.
Initialize flexcom8 with required pincontrol and move the eeproms accordingly.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>