common: cmd_elf.c: use uintptr_t for casts from u32 to void*

This fixes warnings when compiling with ELDK-5.2.1 for MIPS64:

cmd_elf.c: In function 'load_elf_image_phdr':
cmd_elf.c:289:15: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
cmd_elf.c: In function 'load_elf_image_shdr':
cmd_elf.c:343:12: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
cmd_elf.c:346:12: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]

Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
diff --git a/common/cmd_elf.c b/common/cmd_elf.c
index 970426f..a667a46 100644
--- a/common/cmd_elf.c
+++ b/common/cmd_elf.c
@@ -284,7 +284,7 @@
 
 	/* Load each program header */
 	for (i = 0; i < ehdr->e_phnum; ++i) {
-		void *dst = (void *) phdr->p_paddr;
+		void *dst = (void *)(uintptr_t) phdr->p_paddr;
 		void *src = (void *) addr + phdr->p_offset;
 		debug("Loading phdr %i to 0x%p (%i bytes)\n",
 			i, dst, phdr->p_filesz);
@@ -339,10 +339,11 @@
 		}
 
 		if (shdr->sh_type == SHT_NOBITS) {
-			memset((void *)shdr->sh_addr, 0, shdr->sh_size);
+			memset((void *)(uintptr_t) shdr->sh_addr, 0,
+				shdr->sh_size);
 		} else {
 			image = (unsigned char *) addr + shdr->sh_offset;
-			memcpy((void *) shdr->sh_addr,
+			memcpy((void *)(uintptr_t) shdr->sh_addr,
 				(const void *) image,
 				shdr->sh_size);
 		}