PCI: mvebu: Use of_get_available_child_count()
PCI: mvebu: Use of_get_available_child_count()

Rather than open-coding of_get_available_child_count(), use the provided
helper instead.

Tested-by: Thomas Petazzoni <a5d87d2bd7c424ee5cbdb4e978635bf653d5a005@free-electrons.com> (Armada XP GP)
Tested-by: Andrew Lunn <02e0a999c50b1f88df7a8f5a04e1b76b35ea6a88@lunn.ch> (Kirkwood DIR665)
Signed-off-by: Russell King <f6aa0246ff943bfa8602cdf60d40c481b38ed232@arm.linux.org.uk>
Signed-off-by: Bjorn Helgaas <f10ec01be0c6b54271af5c550cd257810bdf3268@google.com>
Reviewed-by: Thomas Petazzoni <a5d87d2bd7c424ee5cbdb4e978635bf653d5a005@free-electrons.com>
KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs