fsl/fman: Validate cell-index value obtained from Device Tree

fsl/fman: Validate cell-index value obtained from Device Tree

Cell-index value is obtained from Device Tree and then used to calculate
the index for accessing arrays port_mfl[], mac_mfl[] and intr_mng[].
In case of broken DT due to any error cell-index can contain any value
and it is possible to go beyond the array boundaries which can lead
at least to memory corruption.

Validate cell-index value obtained from Device Tree.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Reviewed-by: Sean Anderson <sean.anderson@seco.com>
Signed-off-by: Aleksandr Mishin <amishin@t-argos.ru>
Link: https://patch.msgid.link/20241028065824.15452-1-amishin@t-argos.ru
Signed-off-by: Jakub Kicinski <kuba@kernel.org>