C-SKY: fix sigcontext miss match

C-SKY defines SIGCONTEXT as siginfo_t *_si, struct ucontext_t * for
__profil_counter.  ucontext_t get an extra __mask field which is miss
match with the struct sigcontext from linux kernel.  The time value
from gprof report will be always zero without this patch.  This
patch also fix the registers sequence in register-dump.h.

	* sysdeps/unix/sysv/linux/csky/register-dump.h: Adjust offset change.
	* sysdeps/unix/sysv/linux/csky/sys/ucontext.h: Remove __mask field
	in mcontext_t