microblaze: Remove duplicate declarations of _stext[] and _etext[]

They're already provided by <asm/sections.h>.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: microblaze-uclinux@itee.uq.edu.au
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/microblaze/include/asm/sections.h

@@ -16,7 +16,6 @@
 # ifndef __ASSEMBLY__
 extern char _ssbss[], _esbss[];
 extern unsigned long __ivt_start[], __ivt_end[];
-extern char _etext[], _stext[];
 
 extern u32 _fdt_start[], _fdt_end[];