ARM: qcom_defconfig: Enable Z2 Tablet related options

Select the options necessary to get USB, coincell, WiFI, touchscreen and
backlight on the Z2 Tablet (and other family B devices) working. The
device specific peripherals are selected as modules.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>