ARM: 8554/1: kernel: pci: remove pci=firmware command line parameter handling

ARM: 8554/1: kernel: pci: remove pci=firmware command line parameter handling

According to kernel documentation, the pci=firmware command line
parameter is only meant to be used on IXP2000 ARM platforms to prevent
the kernel from assigning PCI resources configured by the bootloader.

Since the IXP2000 ARM platforms support has been removed from the
kernel in commit:

commit c65f2abf54a6 ("ARM: remove ixp23xx and ixp2000 platforms")

its platforms specific kernel parameters should be removed
too from the kernel documentation along with the kernel code
currently handling them in that they have just become obsolete.

This patch removes the pci=firmware command line parameter handling
from ARM code and the related kernel parameters documentation
section.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Lennert Buytenhek <kernel@wantstofly.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Lennert Buytenhek <kernel@wantstofly.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>