ARM: integrator: set V4T and V5 as default multitargets

When switching the Integrator machines to multiplatform, the
V7 target becomes default, but most Integrators are V4T or V5,
so set these two as default in the defconfig and deselect V7.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>