PSA_CRYPTO_DRIVER_TEST_ALL is incompatible with MBEDTLS_PSA_CRYPTO_CONFIG

Explain how PSA_CRYPTO_DRIVER_TEST_ALL works and why we have it. Note that
it is incompatible with MBEDTLS_PSA_CRYPTO_CONFIG.

MBEDTLS_PSA_CRYPTO_BUILTIN_KEYS is in the full config, so there's no need to
add it explicitly.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index 7da895b..ae8dae5 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -2916,17 +2916,16 @@
 }
 
 component_test_psa_crypto_drivers () {
-    msg "build: MBEDTLS_PSA_CRYPTO_DRIVERS w/ driver hooks"
+    msg "build: full + test drivers dispatching to builtins"
     scripts/config.py full
     scripts/config.py set MBEDTLS_PSA_CRYPTO_DRIVERS
-    scripts/config.py set MBEDTLS_PSA_CRYPTO_BUILTIN_KEYS
     loc_cflags="$ASAN_CFLAGS -DPSA_CRYPTO_DRIVER_TEST_ALL"
     loc_cflags="${loc_cflags} '-DMBEDTLS_USER_CONFIG_FILE=\"../tests/configs/user-config-for-test.h\"'"
     loc_cflags="${loc_cflags} -I../tests/include -O2"
 
     make CC=gcc CFLAGS="${loc_cflags}" LDFLAGS="$ASAN_CFLAGS"
 
-    msg "test: full + MBEDTLS_PSA_CRYPTO_DRIVERS"
+    msg "test: full + test drivers dispatching to builtins"
     make test
 }