octeontx2: cn10k: fix RX flowid TCAM mask handling

The RX flowid programming initializes the TCAM mask to all ones, but
then overwrites it when clearing the MAC DA mask bits. This results
in losing the intended initialization and may affect other match fields.

Update the code to clear the MAC DA bits using an AND operation, making
the handling of mask[0] consistent with mask[1], where the field-specific
bits are cleared after initializing the mask to ~0ULL.

Fixes: 57d00d4 ("octeontx2-pf: mcs: Match macsec ethertype along with DMAC")
Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Reviewed-by: Subbaraya Sundeep <sbhatta@marvell.com>
Link: https://patch.msgid.link/20260116164724.2733511-1-alok.a.tiwari@oracle.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: aloktiwa

drivers/net/ethernet/marvell/octeontx2/nic/cn10k_macsec.c

@@ -328,7 +328,7 @@ static int cn10k_mcs_write_rx_flowid(struct otx2_nic *pfvf,
 
 	req->data[0] = FIELD_PREP(MCS_TCAM0_MAC_DA_MASK, mac_da);
 	req->mask[0] = ~0ULL;
-	req->mask[0] = ~MCS_TCAM0_MAC_DA_MASK;
+	req->mask[0] &= ~MCS_TCAM0_MAC_DA_MASK;
 
 	req->data[1] = FIELD_PREP(MCS_TCAM1_ETYPE_MASK, ETH_P_MACSEC);
 	req->mask[1] = ~0ULL;