PDP10/11: Fix build warnings on OS/X

PDP11/pdp11_io_lib.c: In function 'show_iospace':
PDP11/pdp11_io_lib.c:363: warning: too few arguments for format

PDP10/pdp10_lp20.c: In function 'lp20_set_vfu_type':
PDP10/pdp10_lp20.c:1038: warning: implicit declaration of function 'toupper'
PDP10/pdp10_lp20.c:1121: warning: implicit declaration of function 'isspace'