hw/arm/strongarm.c: convert DPRINTF to trace events and guest errors

hw/arm/strongarm.c: convert DPRINTF to trace events and guest errors

Tracing DPRINTFs to stderr might not be desired. A developer that relies
on trace events should be able to opt-in to each trace event and rely on
QEMU's log redirection, instead of stderr by default.

This commit converts DPRINTFs in this file that are used for tracing
into trace events. DPRINTFs that report guest errors are logged with
LOG_GUEST_ERROR.#

Signed-off-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 39db71dd87bf2007cf7812f3d91dde53887f1f2f.1706544115.git.manos.pitsidianakis@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>