s390/mm: provide simple ARCH_HAS_DEBUG_VIRTUAL support

Provide a very simple ARCH_HAS_DEBUG_VIRTUAL implementation.
For now errors are only reported for the following cases:

- Trying to translate a vmalloc or module address to a physical address

- Translating a supposed to be ZONE_DMA virtual address into a physical
address, and the resulting physical address is larger than two GiB

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/cio: introduce bitwise dma types and helper functions

Introduce dma32_t and dma64_t bitwise types, which are supposed to be used
for 31 and 64 bit DMA capable addresses. This allows to use sparse (make
C=1) for type checking, so that incorrect usages can be easily found.

Also add a couple of helper functions which
- convert virtual to DMA addresses and vice versa
- allow for simple logical and arithmetic operations on DMA addresses
- convert DMA addresses to plain u32 and u64 values

All helper functions exist to avoid excessive casting in C code.

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Co-developed-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>