[Mellanox] Disable IOMMU for SN4280 platform (#20271)

- Why I did it
Disable amd_iommu cmdline option to improve the bootup time after kexec from 60 sec to < 10 sec.

- How I did it

- How to verify it
Verified Warm-reboot is finishing much earlier
Ran the sonic-mgmt test suite and verified no issue.

Signed-off-by: Vivek Reddy <vkarri@nvidia.com>

Author: vivekrnv

device/mellanox/x86_64-nvidia_sn4280-r0/installer.conf

@@ -1 +1 @@
-ONIE_PLATFORM_EXTRA_CMDLINE_LINUX="libata.force=noncq module_blacklist=mlx5_ib,mlx5_core ima_hash=sha384"
+ONIE_PLATFORM_EXTRA_CMDLINE_LINUX="libata.force=noncq module_blacklist=mlx5_ib,mlx5_core ima_hash=sha384 amd_iommu=off"