Remove pseudo targets for building shared libs

Thanks to the change "build: support library builds via lib/<libname>",
shared libraries can now be built directly by the build system.

Issue #4599

repos/base-fiasco/recipes/src/base-fiasco/content.mk

@@ -21,6 +21,5 @@ content:
 	for spec in x86_32; do \
 	  mv lib/mk/spec/$$spec/ld-fiasco.mk lib/mk/spec/$$spec/ld.mk; \
 	  done;
-	sed -i "s/ld-fiasco/ld/"     src/lib/ld/fiasco/target.mk
 	sed -i "s/fiasco_timer_drv/timer/" src/timer/fiasco/target.mk
 

repos/base-fiasco/src/lib/ld/fiasco/target.mk

@@ -1,2 +0,0 @@
-TARGET = ld-fiasco
-LIBS = ld-fiasco