gpu: nova-core: extract FWSEC from BIOS and patch it to run FWSEC-FRTS

The FWSEC firmware needs to be extracted from the VBIOS and patched with
the desired command, as well as the right signature. Do this so we are
ready to load and run this firmware into the GSP falcon and create the
FRTS region.

[joelagnelf@nvidia.com: give better names to FalconAppifHdrV1's fields]

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://lore.kernel.org/r/20250619-nova-frts-v6-22-ecf41ef99252@nvidia.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

Author: Gnurou

drivers/gpu/nova-core/dma.rs

@@ -2,9 +2,6 @@
 
 //! Simple DMA object wrapper.
 
-// To be removed when all code is used.
-#![expect(dead_code)]
-
 use core::ops::{Deref, DerefMut};
 
 use kernel::device;

drivers/gpu/nova-core/firmware.rs

@@ -15,6 +15,8 @@ use crate::falcon::FalconFirmware;
 use crate::gpu;
 use crate::gpu::Chipset;
 
+pub(crate) mod fwsec;
+
 pub(crate) const FIRMWARE_VERSION: &str = "535.113.01";
 
 /// Structure encapsulating the firmware blobs required for the GPU to operate.
@@ -114,7 +116,6 @@ struct FirmwareDmaObject<F: FalconFirmware, S: SignedState>(DmaObject, PhantomDa
 /// This is module-local and meant for sub-modules to use internally.
 trait FirmwareSignature<F: FalconFirmware>: AsRef<[u8]> {}
 
-#[expect(unused)]
 impl<F: FalconFirmware> FirmwareDmaObject<F, Unsigned> {
     /// Patches the firmware at offset `sig_base_img` with `signature`.
     fn patch_signature<S: FirmwareSignature<F>>(