fpga: altera: Rename Stratix10 FPGA to Intel FPGA SDM Mailbox

fpga: altera: Rename Stratix10 FPGA to Intel FPGA SDM Mailbox

Rename Stratix10 FPGA driver to Intel FPGA SDM Mailbox driver
because it is using generic SDM (Secure Device Manager) Mailbox
interface shared by other platform (e.g. Agilex) as well.

Signed-off-by: Chee Hong Ang <chee.hong.ang@intel.com>
Reviewed-by: Ley Foon Tan <ley.foon.tan@intel.com>