PCI: brcmstb: Assert PERST# on BCM2711

PCI: brcmstb: Assert PERST# on BCM2711

The current PCIe driver assumes PERST# is asserted when probe() is invoked.
Some older versions of the 2711/RPi bootloader left PERST# unasserted, as
the Raspian OS does assert PERST# on probe().  For this reason, we assert
PERST# for BCM2711 SOCs (i.e. RPi).

Link: https://lore.kernel.org/r/20230623144100.34196-5-james.quinlan@broadcom.com
Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>