dmaengine: idxd: wq size configuration needs to check global max size

The current size_store() function for idxd sysfs does not check the total
wq size. This allows configuration of all wqs with total wq size. Add check
to make sure the wq sysfs attribute rejects storing of size over the total
wq size.

Fixes: c52ca478

 ("dmaengine: idxd: add configuration component of driver")
Reported-by: Jerry Chen <jerry.t.chen@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/158213309629.2509.3583411832507185041.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>