flash_map: Increase minimum supported write align via flash_area_align

Signed-off-by: Gustavo Henrique Nihei <gustavo.nihei@espressif.com>
diff --git a/boot/bootutil/src/bootutil_public.c b/boot/bootutil/src/bootutil_public.c
index f9b086f..6ce09d0 100644
--- a/boot/bootutil/src/bootutil_public.c
+++ b/boot/bootutil/src/bootutil_public.c
@@ -370,8 +370,8 @@
         const uint8_t *inbuf, uint8_t inlen)
 {
     uint8_t buf[BOOT_MAX_ALIGN];
-    uint8_t align;
     uint8_t erased_val;
+    uint32_t align;
     int rc;
 
     align = flash_area_align(fap);