net: stmmac: Batch set RX OWN flag and other flags

Minimize access to the RX descriptor by collecting all the flags in a
local variable and then updating the descriptor at once.

Signed-off-by: Tan En De <ende.tan@starfivetech.com>
Link: https://patch.msgid.link/20240831011114.2065912-1-ende.tan@starfivetech.com


Signed-off-by: Paolo Abeni <pabeni@redhat.com>