jmr3904: Simplify bsp_specs

Updates #3250.

c/src/lib/libbsp/mips/jmr3904/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:
-%(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/mips/jmr3904/startup/linkcmds

@@ -10,6 +10,9 @@ RamSize = DEFINED(RamSize) ? RamSize : 4M;
 HeapSize = DEFINED(HeapSize) ? HeapSize : 0x0;
 _StackSize = DEFINED(_StackSize) ? _StackSize : 0x1000;
 
+ENTRY(_start)
+STARTUP(start.o)
+
 SECTIONS
 { 
     . = 0x88000000;