Fixed xcore header to comply with bindings

and fixed whitespace

include/capstone/xcore.h

@@ -64,8 +64,10 @@ typedef enum xcore_reg {
 // Instruction's operand referring to memory
 // This is associated with XCORE_OP_MEM operand type above
 typedef struct xcore_op_mem {
-	xcore_reg base;		// base register
-	xcore_reg index;	// index register
+	uint8_t base;		// base register, can be safely interpreted as
+				// a value of type `xcore_reg`, but it is only
+				// one byte wide
+	uint8_t index;		// index register, same conditions apply here
 	int32_t disp;	// displacement/offset value
 	int     direct;	// +1: forward, -1: backward
 } xcore_op_mem;