Documentation: ocxl.rst: change FPGA indirect article to an

Change use of 'a fpga' to 'an fpga'

Signed-off-by: Tom Rix <[e-mail]>
Acked-by: Andrew Donnellan <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/userspace-api/accelerators/ocxl.rst

···
 at being low-latency and high-bandwidth. The specification is
 developed by the `OpenCAPI Consortium <http://opencapi.org/>`_.
 
-It allows an accelerator (which could be a FPGA, ASICs, ...) to access
+It allows an accelerator (which could be an FPGA, ASICs, ...) to access
 the host memory coherently, using virtual addresses. An OpenCAPI
 device can also host its own memory, that can be accessed from the
 host.