global_data: Reduce the size of mon_len

This is the length of the U-Boot binary, which is typically 200-800KB
and certainly not larger than 4GB. Use a 32-bit value to save space in
global_data and move it up to be with fields of the same alignment.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/asm-generic/global_data.h b/include/asm-generic/global_data.h
index 0c88015..06523ca 100644
--- a/include/asm-generic/global_data.h
+++ b/include/asm-generic/global_data.h
@@ -72,6 +72,10 @@
 	 */
 	unsigned int mem_clk;
 	/**
+	 * @mon_len: monitor length in bytes
+	 */
+	unsigned int mon_len;
+	/**
 	 * @env_addr: address of environment structure
 	 *
 	 * @env_addr contains the address of the structure holding the
@@ -116,10 +120,6 @@
 	 */
 	phys_size_t ram_size;
 	/**
-	 * @mon_len: monitor length in bytes
-	 */
-	unsigned long mon_len;
-	/**
 	 * @irq_sp: IRQ stack pointer
 	 */
 	unsigned long irq_sp;