powerpc/book3e: Fix build error

arch/powerpc/mm/nohash/fsl_book3e.c: In function ‘relocate_init’:
arch/powerpc/mm/nohash/fsl_book3e.c:348:2: error: implicit declaration of function ‘early_get_first_memblock_info’
  early_get_first_memblock_info(__va(dt_ptr), &size);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Add missing include file linux/of_fdt.h to fix this.

Fixes: 86c38fec69 ("powerpc: Remove asm/prom.h from all files that don't need it")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220517094830.27560-1-yuehaibing@huawei.com

arch/powerpc/mm/nohash/fsl_book3e.c

@@ -36,6 +36,7 @@
 #include <linux/delay.h>
 #include <linux/highmem.h>
 #include <linux/memblock.h>
+#include <linux/of_fdt.h>
 
 #include <asm/io.h>
 #include <asm/mmu_context.h>