add new syscall numbers for seccomp, getrandom, memfd_create

these syscalls are new in linux v3.17 and present on all supported
archs except sh.

seccomp was added in commit 48dc92b9fc3926844257316e75ba11eb5c742b2c
it has operation, flags and pointer arguments (if flags==0 then it is
the same as prctl(PR_SET_SECCOMP,...)), the uapi header for flag
definitions is linux/seccomp.h

getrandom was added in commit c6e9d6f38894798696f23c8084ca7edbf16ee895
it provides an entropy source when open("/dev/urandom",..) would fail,
the uapi header for flags is linux/random.h

memfd_create was added in commit 9183df25fe7b194563db3fec6dc3202a5855839c
it allows anon mmap to have an fd, that can be shared, sealed and needs no
mount point, the uapi header for flags is linux/memfd.h

arch/microblaze/bits/syscall.h

@@ -377,6 +377,10 @@
 #define __NR_finit_module 380
 #define __NR_sched_setattr 381
 #define __NR_sched_getattr 382
+#define __NR_renameat2 383
+#define __NR_seccomp 384
+#define __NR_getrandom 385
+#define __NR_memfd_create 386
 
 /* Repeated with SYS_ prefix */
 
@@ -760,3 +764,7 @@
 #define SYS_finit_module 380
 #define SYS_sched_setattr 381
 #define SYS_sched_getattr 382
+#define SYS_renameat2 383
+#define SYS_seccomp 384
+#define SYS_getrandom 385
+#define SYS_memfd_create 386