crypto: jitter - add header to fix buildwarnings

Fix the following build warnings by adding a header for
the definitions shared between jitterentropy.c and
jitterentropy-kcapi.c. Fixes the following:

crypto/jitterentropy.c:445:5: warning: symbol 'jent_read_entropy' was not declared. Should it be static?
crypto/jitterentropy.c:475:18: warning: symbol 'jent_entropy_collector_alloc' was not declared. Should it be static?
crypto/jitterentropy.c:509:6: warning: symbol 'jent_entropy_collector_free' was not declared. Should it be static?
crypto/jitterentropy.c:516:5: warning: symbol 'jent_entropy_init' was not declared. Should it be static?
crypto/jitterentropy-kcapi.c:59:6: warning: symbol 'jent_zalloc' was not declared. Should it be static?
crypto/jitterentropy-kcapi.c:64:6: warning: symbol 'jent_zfree' was not declared. Should it be static?
crypto/jitterentropy-kcapi.c:69:5: warning: symbol 'jent_fips_enabled' was not declared. Should it be static?
crypto/jitterentropy-kcapi.c:74:6: warning: symbol 'jent_panic' was not declared. Should it be static?
crypto/jitterentropy-kcapi.c:79:6: warning: symbol 'jent_memcpy' was not declared. Should it be static?
crypto/jitterentropy-kcapi.c:93:6: warning: symbol 'jent_get_nstime' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Reviewed-by: Stephan Mueller <smueller@chronox.de
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/jitterentropy.c b/crypto/jitterentropy.c
index 9597f9f..042157f 100644
--- a/crypto/jitterentropy.c
+++ b/crypto/jitterentropy.c
@@ -103,12 +103,7 @@ struct rand_data {
  * Helper functions
  ***************************************************************************/
 
-void jent_get_nstime(__u64 *out);
-void *jent_zalloc(unsigned int len);
-void jent_zfree(void *ptr);
-int jent_fips_enabled(void);
-void jent_panic(char *s);
-void jent_memcpy(void *dest, const void *src, unsigned int n);
+#include "jitterentropy.h"
 
 /**
  * Update of the loop count used for the next round of