generic_or1k: Simplify bsp_specs

Updates #3520.

c/src/lib/libbsp/or1k/generic_or1k/bsp_specs

@@ -1,13 +1,9 @@
 %rename endfile old_endfile
 %rename startfile old_startfile
-%rename link old_link
 
 *startfile:
 %{!qrtems: %(old_startfile)} \
-%{!nostdlib: %{qrtems: start.o%s crti.o%s crtbegin.o%s -e _start}}
-
-*link:
-%{!qrtems: %(old_link)} %{qrtems: -dc -dp -N}
+%{!nostdlib: %{qrtems: crti.o%s crtbegin.o%s}}
 
 *endfile:
 %{!qrtems: %(old_endfile)} %{qrtems: crtend.o%s crtn.o%s}

c/src/lib/libbsp/or1k/shared/startup/linkcmds.base

@@ -17,6 +17,7 @@
 OUTPUT_ARCH (or1k)
 
 ENTRY (_start)
+STARTUP (start.o)
 
 /*
  * Global symbols that may be defined externally