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

[ Upstream commit 11d49ce9f7946dfed4dcf5dbde865c78058b50ab ]

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>