ARM: dts: Add PMU dt data to support PMU for exynos4x12

ARM CPU has its own performance profiling unit(PMU, Perforamnce Monitoring Unit).
This patch add PMU dt data to support PMU which count cache hit and miss events.

PMU interrput list of Exynos4212
- <2 2> : INTG2[2] - PMUIRQ[0] for CPU0
- <3 2> : INTG3[2] - PMUIRQ[1] for CPU1

PMU interrput list of Exynos4412
- <2 2> : INTG2[2], PMUIRQ[0] for CPU0
- <3 2> : INTG3[2], PMUIRQ[1] for CPU1
- <18 2> : INTG18[2], PMUIRQ[2] : CPU2
- <19 2> : INTG19[2], PMUIRQ[3] : CPU3

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>