Fixes all.sh script for filesystem IO test build

MBEDTLS_ENTROPY_NV_SEED is dependent on platform code unless an
alternative implementation is provided,  therefore needs to be disabled
in the disabled filesystem IO build.
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index 469827e..f9ee2ee 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -232,6 +232,7 @@
 scripts/config.pl unset MBEDTLS_PLATFORM_FPRINTF_ALT
 scripts/config.pl unset MBEDTLS_PLATFORM_SNPRINTF_ALT
 scripts/config.pl unset MBEDTLS_PLATFORM_EXIT_ALT
+scripts/config.pl unset MBEDTLS_ENTROPY_NV_SEED
 scripts/config.pl unset MBEDTLS_MEMORY_BUFFER_ALLOC_C
 scripts/config.pl unset MBEDTLS_FS_IO
 CC=gcc CFLAGS='-Werror -O0' make