net: mvpp2x: Remove IRQ configuration from U-Boot

Remove IRQ configuration from U-Boot PP driver.
U-Boot don't use interrupts and configuration of IRQ in U-Boot
caused crashes in Linux shared interrupt mode.
Also interrupt use is redundant in RX routine since a single RX
queue is used.

Signed-off-by: Stefan Chulski <stefanc@marvell.com>
Tested-by: iSoC Platform CI <ykjenk@marvell.com>
Reviewed-by: Nadav Haklai <nadavh@marvell.com>
Reviewed-by: Igal Liberman <igall@marvell.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Signed-off-by: Stefan Roese <sr@denx.de>