net: liquidio: fix overflow in octeon_init_instr_queue()

[ Upstream commit cca7b1cfd7b8a0eff2a3510c5e0f10efe8fa3758 ]

The expression `(conf->instr_type == 64) << iq_no` can overflow because
`iq_no` may be as high as 64 (`CN23XX_MAX_RINGS_PER_PF`). Casting the
operand to `u64` ensures correct 64-bit arithmetic.

Fixes: f21fb3ed ("Add support of Cavium Liquidio ethernet adapters")
Signed-off-by: Alexey Nepomnyashih <sdl@nppct.ru>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>