ARM: dts: imx6q: update setting of VDDARM_CAP voltage

According to datasheet, VDD_CACHE_CAP must not exceed VDDARM_CAP
by more than 200mV, as all of i.MX6Q boards' VDD_CACHE_CAP currently
are connected to VDDSOC_CAP, so we need to follow this rule by
increasing VDDARM_CAP's voltage.

Signed-off-by: Anson Huang <b20788@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>