USB: isp1362: fix build failure on ARM systems via irq_flags cleanup

There was some left over #ifdef ARM logic that is outdated but no one
really noticed.  So instead of relying on this tricky logic, properly
load and utilize the platform irq_flags resources.

Reported-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Lothar Wassmann <LW@KARO-electronics.de>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>