powerpc/mpc85xx: Make boot flag effective

bootflag as a parameter is passed to board_init_f().
But it is not actually used in this function.
Make it effective by assigned it to gd->flags.

Signed-off-by: Tang Yuantian <Yuantian.Tang@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>

arch/powerpc/lib/board.c

@@ -366,6 +366,8 @@ void board_init_f(ulong bootflag)
 	memset((void *) gd, 0, sizeof(gd_t));
 #endif
 
+	gd->flags = bootflag;
+
 	for (init_fnc_ptr = init_sequence; *init_fnc_ptr; ++init_fnc_ptr)
 		if ((*init_fnc_ptr) () != 0)
 			hang();