XDMA wrong maximum number of user interrupts in xdma_isr

[i-perminov]

The maximum number of user interrupts is specified as
int max = xdev->h2c_channel_max;
It probably should be xdev->user_max. As a result of this typo the number of user interrupts can't be higher than the number of channels.

[hmaarrfk]

Hello,

My name is Mark Harfouche. I am not affiliated with Xilinx in any way. Over the
years of using QDMA, I've been wanted better community organization.

I've created a fork of dma_ip_drivers which I intend to maintain and work with the
community at large to improve.

The fork can be found https://github.com/hmaarrfk/dma_ip_drivers

For now, I am stating the main goals of the repository in
hmaarrfk#2

If you are interested in working together, feel free to open an issue or PR to
my fork.

Best,

Mark