zipl/boot: discard .eh_frame and .interp input sections

The ELF section `.eh_frame` is used for frame unwinding during, for
example, exception handling and the section `.interp` is used by the
program interpreter. [1] Since no frame unwinding nor a program
interpreter is used for the bootloaders we can discard these input
section.

The content of the (exec|bin) files don't change after this change.

[1] https://refspecs.linuxfoundation.org/LSB_1.2.0/gLSB/specialsections.html

Reviewed-by: Stefan Haberland <sth@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

zipl/boot/stage2.lds.S

@@ -88,6 +88,11 @@ SECTIONS
   }
   __stack_end = .;
 
-  .eh_frame : { *(.eh_frame) }
   .note.gnu.build-id : { *(.note.gnu.build-id) }
+
+  /* Sections to be discarded */
+  /DISCARD/ : {
+    *(.eh_frame)
+    *(.interp)
+  }
 }

zipl/boot/stage3.lds.S

@@ -39,7 +39,6 @@ SECTIONS
   __ex_table_start = .;
   .ex_table : { *(.ex_table) }
   __ex_table_stop = .;
-  .eh_frame : { *(.eh_frame) }
 
   __bss_start = .;
   .bss : { *(.bss) }
@@ -75,4 +74,10 @@ SECTIONS
   .notes : {
   *(.note.*)
   }
+
+  /* Sections to be discarded */
+  /DISCARD/ : {
+    *(.eh_frame)
+    *(.interp)
+  }
 }