bios_table: Stabilise pldm_bios_table_append_pad_checksum_check()

pldm_bios_table_append_pad_checksum_check() is a replacement for
pldm_bios_table_append_pad_checksum(), which used assert() to sanitize
its arguments. pldm_bios_table_append_pad_checksum_check() instead
returns an error.

Use of pldm_bios_table_append_pad_checksum_check() is demonstrated in
the following patch:

https://gerrit.openbmc.org/c/openbmc/pldm/+/64626

Additionally, deprecate pldm_bios_table_append_pad_checksum() now that
there's a stable replacement.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Change-Id: If9fc91ac60477cfb6ba96e377dbf5768a990bd69
diff --git a/src/bios_table.c b/src/bios_table.c
index ec96b82..47c5bae 100644
--- a/src/bios_table.c
+++ b/src/bios_table.c
@@ -954,7 +954,7 @@
 	return size;
 }
 
-LIBPLDM_ABI_STABLE
+LIBPLDM_ABI_DEPRECATED
 size_t pldm_bios_table_append_pad_checksum(void *table, size_t capacity,
 					   size_t size)
 {
@@ -965,7 +965,7 @@
 	return size;
 }
 
-LIBPLDM_ABI_TESTING
+LIBPLDM_ABI_STABLE
 int pldm_bios_table_append_pad_checksum_check(void *table, size_t capacity,
 					      size_t *size)
 {