gve: defer interrupt enabling until NAPI registration

gve: defer interrupt enabling until NAPI registration

Currently, interrupts are automatically enabled immediately upon
request. This allows interrupt to fire before the associated NAPI
context is fully initialized and cause failures like below:

[    0.946369] Call Trace:
[    0.946369]  <IRQ>
[    0.946369]  __napi_poll+0x2a/0x1e0
[    0.946369]  net_rx_action+0x2f9/0x3f0
[    0.946369]  handle_softirqs+0xd6/0x2c0
[    0.946369]  ? handle_edge_irq+0xc1/0x1b0
[    0.946369]  __irq_exit_rcu+0xc3/0xe0
[    0.946369]  common_interrupt+0x81/0xa0
[    0.946369]  </IRQ>
[    0.946369]  <TASK>
[    0.946369]  asm_common_interrupt+0x22/0x40
[    0.946369] RIP: 0010:pv_native_safe_halt+0xb/0x10

Use the `IRQF_NO_AUTOEN` flag when requesting interrupts to prevent auto
enablement and explicitly enable the interrupt in NAPI initialization
path (and disable it during NAPI teardown).

This ensures that interrupt lifecycle is strictly coupled with
readiness of NAPI context.

Cc: stable@vger.kernel.org
Fixes: 1dfc2e46117e ("gve: Refactor napi add and remove functions")
Signed-off-by: Ankit Garg <nktgrg@google.com>
Reviewed-by: Jordan Rhee <jordanrhee@google.com>
Reviewed-by: Joshua Washington <joshwash@google.com>
Signed-off-by: Harshitha Ramamurthy <hramamurthy@google.com>
Link: https://patch.msgid.link/20251219102945.2193617-1-hramamurthy@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>