ARM: dts: add hsotg device node for exynos4

This patch adds a hsotg node for exynos4 USB2.0 device controller.

Cc: Tomasz Figa <t.figa@samsung.com>
Cc: Kamil Debski <k.debski@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Chanho Park <chanho61.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>