net: ena: fix incorrect update of intr_delay_resolution

net: ena: fix incorrect update of intr_delay_resolution

BugLink: https://bugs.launchpad.net/bugs/1853180
ena_dev->intr_moder_rx/tx_interval save the intervals received from the
user after dividing them by ena_dev->intr_delay_resolution. Therefore
when intr_delay_resolution changes, the code needs to first mutiply
intr_moder_rx/tx_interval by the previous intr_delay_resolution to get
the value originally given by the user, and only then divide it by the
new intr_delay_resolution.

Current code does not first multiply intr_moder_rx/tx_interval by the old
intr_delay_resolution. This commit fixes it.

Also initialize ena_dev->intr_delay_resolution to be 1.

Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 79226cea4a5ebbd84a4eee1762526f664c7beb62)
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Acked-by: Khaled Elmously <khalid.elmously@canonical.com>
Acked-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>