ARM: dts: gemini: add device_type on pci

[ Upstream commit 483f3645b3f7acfd1c78a19d51b80c0656161974 ]

Fixes DT warning on pci node by adding the missing device_type.

Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>