Move new files to their correct location

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
diff --git a/library/bignum_core_invasive.h b/tf-psa-crypto/drivers/builtin/src/bignum_core_invasive.h
similarity index 100%
rename from library/bignum_core_invasive.h
rename to tf-psa-crypto/drivers/builtin/src/bignum_core_invasive.h
diff --git a/library/bignum_internal.h b/tf-psa-crypto/drivers/builtin/src/bignum_internal.h
similarity index 100%
rename from library/bignum_internal.h
rename to tf-psa-crypto/drivers/builtin/src/bignum_internal.h