k3_gen_x509_cert: Make SWRV configurable for anti-rollback protection

The x509 certificate SWRV is currently hard-coded to 0. This need to be
updated to 1 for j721e 1.1, j7200 and am64x. It is don't care for other
k3 devices.

Added new config K3_X509_SWRV to k3. Default is set to 1.

Signed-off-by: Yogesh Siraswar <yogeshs@ti.com>
Reviewed-by: Dave Gerlach <d-gerlach@ti.com>