mfd: bcm2835-pm: Add BCM2712 PM device support

mfd: bcm2835-pm: Add BCM2712 PM device support

The BCM2712 SoC includes a power management block that serves as the
power domain for the V3D graphics block. Unlike other PM blocks in
the BCM2835 family, it does not feature an ASB register space.

Conditionally register the PM device depending on the SoC variant.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>
Co-developed-by: Stanimir Varbanov <svarbanov@suse.de>
Signed-off-by: Stanimir Varbanov <svarbanov@suse.de>
Signed-off-by: Andrea della Porta <andrea.porta@suse.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://patch.msgid.link/c0b5793868f138bf5c928a12b2763d3e183e2e59.1772839224.git.andrea.porta@suse.com
Signed-off-by: Lee Jones <lee@kernel.org>