USB: isp1760: Fix probe in PCI glue code

USB: isp1760: Fix probe in PCI glue code

This is the backported version of the upstream commit
Stefan Bader <stefan.bader@canonical.com> did the backport

Contains fixes so probe on x86 PCI runs, apparently I'm first to try
this. Several fixes to memory access to probe host scratch register.
Previously would bug check on chip_addr var used uninitialized.
Scratch reg write failed in one instance due to 16-bit initial access
mode, so added "& 0x0000ffff" to the readl as fix.
Includes some general cleanup - remove global vars, organize memory map
resource use.

Signed-off-by: Karl Bongers <kbongers@jged.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>