sim: build: stop passing down SIM_PRIMARY_TARGET

This was needed when the install step was run in subdirs, but now
that we process that entirely in the top-level, we don't need to
pass this down, so drop it.

sim/Makefile.am

@@ -27,7 +27,7 @@ srcroot = $(srcdir)/..
 SUBDIRS = @subdirs@ $(SIM_SUBDIRS)
 
 SIM_PRIMARY_TARGET = @SIM_PRIMARY_TARGET@
-AM_MAKEFLAGS = SIM_PRIMARY_TARGET=$(SIM_PRIMARY_TARGET)
+AM_MAKEFLAGS =
 
 ## We don't set some of these vars here, but we need to define them so they may
 ## be used consistently in local.mk files we include below.

sim/Makefile.in

@@ -1164,7 +1164,7 @@ GNULIB_PARENT_DIR = ..
 srccom = $(srcdir)/common
 srcroot = $(srcdir)/..
 SUBDIRS = @subdirs@ $(SIM_SUBDIRS)
-AM_MAKEFLAGS = SIM_PRIMARY_TARGET=$(SIM_PRIMARY_TARGET)
+AM_MAKEFLAGS = 
 pkginclude_HEADERS = $(am__append_1)
 noinst_LIBRARIES = $(SIM_COMMON_LIB) $(am__append_3)
 CLEANFILES = common/version.c common/version.c-stamp \