powerpc: Delete unused function delete_fdt_mem_rsv()

delete_fdt_mem_rsv() defined in "arch/powerpc/kexec/file_load.c"
has been renamed to fdt_find_and_del_mem_rsv(), and moved to
"drivers/of/kexec.c".

Remove delete_fdt_mem_rsv() in "arch/powerpc/kexec/file_load.c".

Co-developed-by: Prakhar Srivastava <[e-mail]>
Signed-off-by: Prakhar Srivastava <[e-mail]>
Signed-off-by: Lakshmi Ramasubramanian <[e-mail]>
Reviewed-by: Thiago Jung Bauermann <[e-mail]>
Signed-off-by: Rob Herring <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

arch/powerpc/include/asm/kexec.h

···
 int setup_purgatory(struct kimage *image, const void *slave_code,
 		    const void *fdt, unsigned long kernel_load_addr,
 		    unsigned long fdt_load_addr);
-int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size);
 
 #ifdef CONFIG_PPC64
 struct kexec_buf;

arch/powerpc/kexec/file_load.c

···
 
 	return 0;
 }
-
-/**
- * delete_fdt_mem_rsv - delete memory reservation with given address and size
- *
- * Return: 0 on success, or negative errno on error.
- */
-int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size)
-{
-	int i, ret, num_rsvs = fdt_num_mem_rsv(fdt);
-
-	for (i = 0; i < num_rsvs; i++) {
-		uint64_t rsv_start, rsv_size;
-
-		ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size);
-		if (ret) {
-			pr_err("Malformed device tree.\n");
-			return -EINVAL;
-		}
-
-		if (rsv_start == start && rsv_size == size) {
-			ret = fdt_del_mem_rsv(fdt, i);
-			if (ret) {
-				pr_err("Error deleting device tree reservation.\n");
-				return -EINVAL;
-			}
-
-			return 0;
-		}
-	}
-
-	return -ENOENT;
-}