crypto/fsl: export caam_get_era()

We need the era in other modules, too. For example, to get the RNG
version.

Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>

include/fsl_sec.h

@@ -316,6 +316,8 @@ int blob_dek(const u8 *src, u8 *dst, u8 len);
 int sec_init_idx(uint8_t);
 #endif
 int sec_init(void);
+
+u8 caam_get_era(void);
 #endif
 
 #endif /* __FSL_SEC_H */