zynq: Remove reference to gdata

The global_data pointer (gd) has already been set before board_init_f()
is called. We should not assign it again. We should also not use gdata since
it is going away.

Signed-off-by: Simon Glass <sjg@chromium.org>

arch/arm/cpu/armv7/zynq/spl.c

@@ -20,9 +20,6 @@ void board_init_f(ulong dummy)
 	/* Clear the BSS. */
 	memset(__bss_start, 0, __bss_end - __bss_start);
 
-	/* Set global data pointer. */
-	gd = &gdata;
-
 	preloader_console_init();
 	arch_cpu_init();
 	board_init_r(NULL, 0);