lasips2: rename lasips2_init() to lasips2_initfn() and update it to return the LASIPS...

lasips2: rename lasips2_init() to lasips2_initfn() and update it to return the LASIPS2 device

When QOMifying a device it is typical to use _init() as the suffix for an
instance_init function, however this name is already in use by the legacy LASIPS2
wrapper function. Eventually the wrapper function will be removed, but for now
rename it to lasips2_initfn() to avoid a naming collision.

At the same time update lasips2_initfn() return the LASIPS2 device so that it
can later be accessed using qdev APIs by the HPPA machine.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Acked-by: Helge Deller <deller@gmx.de>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220624134109.881989-41-mark.cave-ayland@ilande.co.uk>