net/ibmvnic: Fix EOI when running in XIVE mode.

commit 11d49ce9 upstream.

pSeries machines on POWER9 processors can run with the XICS (legacy)
interrupt mode or with the XIVE exploitation interrupt mode. These
interrupt contollers have different interfaces for interrupt
management : XICS uses hcalls and XIVE loads and stores on a page.
H_EOI being a XICS interface the enable_scrq_irq() routine can fail
when the machine runs in XIVE mode.

Fix that by calling the EOI handler of the interrupt chip.

Fixes: f23e0643

 ("ibmvnic: Clear pending interrupt after device reset")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>