ARM: dts: cleanup exynos5440.dtsi

remove duplicated compatible

Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Merge branch 'next/cleanup-s3c' into for-next
Merge branch 'next/cleanup-s5p' into for-next
Merge branch 'next/timer-samsung' into for-next
Merge branch 'next/irq-s3c24xx' into for-next
Merge branch 'next/pinctrl-exynos' into for-next