hw/arm: move CONFIG_V7M out of default-devices

hw/arm: move CONFIG_V7M out of default-devices

We currently select CONFIG_V7M for a bunch of our m-profile devices.
The last sticking point is translate.c which cannot be compiled
without expecting v7m support. Express this dependency in Kconfig
rather than in default devices as a stepping stone to a fully
configurable translate.c.

While we are at it we also need to select ARM_COMPATIBLE_SEMIHOSTING
as that is implied for M profile machines.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210707131744.26027-4-alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>