Michael Brown
f8e1678b84
[crypto] Allow cross-certificate source to be configured at build time
Provide a build option CROSSCERT in config/crypto.h to allow the
default cross-signed certificate source to be configured at build
time. The ${crosscert} setting may still be used to reconfigure the
cross-signed certificate source at runtime.
Signed-off-by: Michael Brown <mcb30@ipxe.org>