Avoid emitting a PT_INTERP section for powerpc64 kernels and arrange for

the first instruction to be at the start of the text segment. This allows
the kernel to be booted correctly by stock kexec-lite.

MFC after:	2 weeks

sys/conf/ldscript.powerpc64

@@ -10,7 +10,7 @@ SECTIONS
 {
   /* Read-only sections, merged into text segment: */
 
-  . = kernbase + SIZEOF_HEADERS;
+  . = kernbase;
   PROVIDE (begin = . - SIZEOF_HEADERS);
 
   .text      :
@@ -24,7 +24,10 @@ SECTIONS
   _etext = .;
   PROVIDE (etext = .);
 
-  .interp     : { *(.interp) 	}
+  /* Do not emit PT_INTERP section, which confuses some loaders (kexec-lite) */
+  .interpX    : { *(.interp) 	} : NONE
+  /DISCARD/   : { *(.interp)	} 
+
   .hash          : { *(.hash)		}
   .dynsym        : { *(.dynsym)		}
   .dynstr        : { *(.dynstr)		}