arm64: dts: renesas: hihope-rzg2-ex: Let the board specific DT decide about pciec1

arm64: dts: renesas: hihope-rzg2-ex: Let the board specific DT decide about pciec1

The plan for the HiHope RZ/G2N board is to enable pciec0 by default,
and use pciec1 physical interface for SATA (as SATA and PCIE1 share
the same physical interface), therefore move pciec1 enabling away
from hihope-rzg2-ex.

Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Link: https://lore.kernel.org/r/1570178133-21532-8-git-send-email-fabrizio.castro@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>