ARM: dts: berlin2cd: fix local timer interrupt flags

Use the correct trigger type for Cortex-A9. This was fixed for several
other SoCs since the kernel started issuing a boot-time warning.

Signed-off-by: Alexander Monakov <amonakov@ispras.ru>
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>