USB: Fix usb/isp1760 build on sparc

This commit:

commit 8f5d621543cb064d2989fc223d3c2bc61a43981e
Author: Joachim Foerster <joachim.foerster@missinglinkelectronics.com>
Date:   Mon Oct 10 18:06:54 2011 +0200

    usb/isp1760: Let OF bindings depend on general CONFIG_OF instead of PPC_OF .

    To be able to use the driver on other OF-aware architectures, too.
    And add necessary OF related #includes to fix compilation error.

    Signed-off-by: Joachim Foerster <joachim.foerster@missinglinkelectronics.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
enabled the build on all CONFIG_OF architectures, but it cannot do
this.

This driver depends upon CONFIG_OF_IRQ but not all CONFIG_OF platforms
support that infrastructure, in particular Sparc does not so the
build fails.

Please push a patch like the following to Linus so that this code only
gets built where it actually should.

--------------------
usb/isp1760: Add missing CONFIG_OF_IRQ dependency on OF code.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>