arm64: dts: exynos: Fix invalid GIC interrupt flags in exynos7

Interrupt of type IRQ_TYPE_NONE is not allowed for GIC interrupts and
generates an error:
	genirq: Setting trigger mode 0 for irq 16 failed (gic_set_type+0x0/0x68)

The GIC requires shared interrupts to be edge rising or level high.
Platform declares support for both.  Arbitrarily choose level high
everywhere hoping it will work on each platform.

Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reported-by: Alban Browaeys <alban.browaeys@gmail.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Tested-by: Alim Akhtar <alim.akhtar@samsung.com>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>