drivers: net: davinci_cpdma: acknowledge interrupt properly

CPDMA interrupts are not properly acknowledged which leads to interrupt
storm, only cpdma interrupt 0 is acknowledged in Davinci CPDMA driver.
Changed cpdma_ctlr_eoi api to acknowledge 1 and 2 interrupts which are
used for rx and tx respectively.

Reported-by: Pantelis Antoniou <panto@antoniou-consulting.com>
Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>