ARM: mvebu: Select corediv clk for all mvebu v7 SoC

Since the commit bd3677ff ("clk: mvebu: Remove corediv clock from
Armada XP"), the corediv clk is no more selected for Armada XP, however
this clock is used for Armada XP using the compatible
armada-370-corediv-clock.

While since commit 1594d568 ("clk: mvebu: Move corediv config to
mvebu config") Armada 38x and Armada 375 got corediv support again, not
only Armada XP was missed but also Armada 39x.

Actually all the SoC selecting MVEBU_V7 config need this clock:
git grep "\-corediv-clock" arch/arm/boot/dts
arch/arm/boot/dts/armada-370-xp.dtsi: compatible = "marvell,armada-370-corediv-clock";
arch/arm/boot/dts/armada-375.dtsi:    compatible = "marvell,armada-375-corediv-clock";
arch/arm/boot/dts/armada-38x.dtsi:    compatible = "marvell,armada-380-corediv-clock";
arch/arm/boot/dts/armada-39x.dtsi:    compatible = "marvell,armada-390-corediv-clock"

This commit now fixes this behavior by letting MVEBU_V7 select
MVEBU_CLK_COREDIV.

Fixes: bd3677ff ("clk: mvebu: Remove corediv clock from Armada XP")
Cc: stable@vger.kernel.org
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>