Revert "net/ibmvnic: Fix EOI when running in XIVE mode"

This reverts commit 11d49ce9


(“net/ibmvnic: Fix EOI when running in XIVE mode.”) since that
has the unintended effect of changing the interrupt priority
and emits warning when running in legacy XICS mode.

Signed-off-by: Juliet Kim <julietk@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>