fix(draw_buf): use LV_ROUND_UP to align draw buffer address

From test config lv_test_conf.h:

/*Use non power of 2 to avoid the case when `malloc` returns aligned pointer by default, and use a large value be sure any issues will cause crash*/
\#define LV_DRAW_BUF_ALIGN                       852

We need to support non-power-of-2 draw buffer alignement.
Introduce LV_ROUND_UP in lv_math.h and use it instead.

Signed-off-by: Xu Xingliang <xuxingliang@xiaomi.com>

src/misc/lv_math.h

@@ -29,6 +29,9 @@ extern "C" {
 /*Align up value x to align, align must be a power of two*/
 #define LV_ALIGN_UP(x, align) (((x) + ((align) - 1)) & ~((align) - 1))
 
+/*Round up value x to round, round can be any integer number*/
+#define LV_ROUND_UP(x, round) ((((x) + ((round) - 1)) / (round)) * (round))
+
 /**********************
  *      TYPEDEFS
  **********************/