hw/arm/bcm2835: Drop futile attempts at QOM-adopting memory

hw/arm/bcm2835: Drop futile attempts at QOM-adopting memory

The "bcm2835-peripherals" device's .instance_init() method
bcm2835_peripherals_init() attempts to make two memory regions QOM
children of the device.  This is futile, because memory_region_init()
already did.  The errors are ignored (a later commit will change
that).  Drop the useless calls.

Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Andrew Baumann <Andrew.Baumann@microsoft.com>
Cc: "Philippe Mathieu-Daudé" <philmd@redhat.com>
Cc: qemu-arm@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200505152926.18877-13-armbru@redhat.com>