[PATCH] PCI: iproc: fix 32-bit build error

Arnd Bergmann [off-list ref] writes:

The iproc PCI driver tries to figure out whether the MMIO window has
a valid size, but does this using a 64-bit modulo operation, which
is not allowed on 32-bit kernels and leads to a link error:

drivers/built-in.o: In function `iproc_pcie_setup':
:(.text+0x4b798): undefined reference to `__aeabi_uldivmod'

This works around that error by using the div64_u64() function
provided by the kernel. While this is an expensive operation,
it is harmless because we only call it during the probing
of the driver.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 0ab99ca8eb6c ("PCI: iproc: Fix compile warnings")

Tested-by: Kevin Hilman <redacted>

Verified that this fixes the build failure on arm multi_v7_defconfig +
CONFIG_ARM_LPAE=y on top of next-20151013.

Kevin