platform/x86/amd/pmf: Fix the custom bios input handling mechanism

platform/x86/amd/pmf: Fix the custom bios input handling mechanism

Originally, the 'amd_pmf_get_custom_bios_inputs()' function was written
under the assumption that the BIOS would only send a single pending
request for the driver to process. However, following OEM enablement, it
became clear that multiple pending requests for custom BIOS inputs might
be sent at the same time, a scenario that the current code logic does not
support when it comes to handling multiple custom BIOS inputs.

To address this, the code logic needs to be improved to not only manage
multiple simultaneous custom BIOS inputs but also to ensure it is scalable
for future additional inputs.

Co-developed-by: Patil Rajesh Reddy <Patil.Reddy@amd.com>
Signed-off-by: Patil Rajesh Reddy <Patil.Reddy@amd.com>
Tested-by: Yijun Shen <Yijun.Shen@Dell.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Link: https://patch.msgid.link/20250901110140.2519072-3-Shyam-sundar.S-k@amd.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>