Fix the setting of the next adjacent fields in descriptors.

Following commit 5faf23ec the next_adj field of all descriptors is set
according to the index of the descriptor rather than its address which
causes issues when dma_alloc_coherent doesn't return an address which is
page aligned (which happens).
Moreover, in the case of a transfer which number of descriptors is
bigger than a full page, the next_adj field is set to the maximum (63)
for all descriptors untill the last page of descriptors where it starts
decreasing.
Last, even before this commit, the next_adj field inside a block of
adjacent descriptors is not decreasing untill coming near page end,
which is not compliant with what the documentation says :

"Every descriptor in the descriptor list must accurately describe the descriptor
or block ofdescriptors that follows. In a block of adjacent descriptors, the
Nxt_adj value decrements from the first descriptor to the second to last
descriptor which has a value of zero. Likewise, eachdescriptor in the block
points to the next descriptor in the block, except for the last descriptor
which might point to a new block or might terminate the list."

This commit aligns the blocks of adjacent descriptors to
XDMA_MAX_ADJ_BLOCK_SIZE and makes the next_adj field decrease inside
each block untill the second to last descriptor in the block or in the
full transfer. The size of the page being a multiple of the size of the
block (4096 = sizeof(xdma_desc) * 128 =
sizeof(xdma_desc) * 2 * XDMA_MAX_ADJ_BLOCK_SIZE

Resolved HW errors observed with QDMA4.0 MM only design

Fix wrong user irq max

xdma_thread: fix cpu node bug

XDMA: increase nxt_adj to 0x3F (max. allowed) and fixed nxt_adj setting when last descriptor does not fall on the page boundary

2020.1 QDMA Linux Driver Release Updated

2020.1 DPDK Release notes updated

2020.1 QDMA Linux, DPDK and Windows Drivers are common drivers which supports the QDMA4.0 and QDMA3.1 Designs

User irq max was incorrectly set to h2c_channel_max

The number of threads is arbitrarily set to 8 and we iterate over 8 cpus
without knowing if we really have 8 cpus. This causes a call to
cpu_to_node with an index that is out of bound, thus returning an
undefined number, which crashes later when calling
kthread_create_on_node.
Fix this by iterating over the online cpus stopping when reaching the
number of threads that is specified.

Updated 2019.2 documentation path

Fixes a design error revealed by running on aarch64

Fix building for Linux 5.0 and newer

Fix a Linux crash when pci_msix_vec_count() returns -EINVAL

Simply put, you cannot call wait_event_interruptible_timeout while
holding a spin_lock. The reason the driver got away with this on
x86 is because the hardware is somehow fast enough so that the
condition is never false and hence no scheduling ever needs to
occur.

Updated the comments for #defines in libqdma_export.h for 2019.2 release

Also described in https://github.com/Xilinx/dma_ip_drivers/issues/45

Removed the stale qdma_reg_dump.h file reference from Makefile.

QDMA Linux reference driver for 2019.2 release

Co-Authored-By: sujathabanoth-xlnx <sujathabanoth-xlnx@users.noreply.github.com>

Updated DPDK release notes with a known issue