scsi: firmware: xilinx: Add support for secure read/write ioctl interface

scsi: firmware: xilinx: Add support for secure read/write ioctl interface

Add support for a generic ioctl read/write interface using which users
can request firmware to perform read/write operations on a protected and
secure address space.

The functionality is introduced through the means of two new IOCTL IDs
which extend the existing PM_IOCTL EEMI API:

 - IOCTL_READ_REG
 - IOCTL_MASK_WRITE_REG

The caller only passes the node id of the given device and an offset.
The base address is not exposed to the caller and internally retrieved
by the firmware. Firmware will enforce an access policy on the incoming
read/write request.

Signed-off-by: Izhar Ameer Shaikh <izhar.ameer.shaikh@amd.com>
Reviewed-by: Tanmay Shah <tanmay.shah@amd.com>
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
Signed-off-by: Ajay Neeli <ajay.neeli@amd.com>
Acked-by: Senthil Nathan Thangaraj <senthilnathan.thangaraj@amd.com>
Acked-by: Michal Simek <michal.simek@amd.com>
Acked-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20251021113003.13650-3-ajay.neeli@amd.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>