qcacmn: Use qdf flex mem to allocate rx ppdu info

To avoid fragmentation, use qdf flex mem framework
to allocate rx ppdu info

CRs-Fixed: 3230970
Change-Id: I2318f6c5f33e5337f6398263d6717da698be7c92

qdf/inc/qdf_flex_mem.h

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2018-2019 The Linux Foundation. All rights reserved.
+ * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
  *
  * Permission to use, copy, modify, and/or distribute this software for
  * any purpose with or without fee is hereby granted, provided that the
@@ -51,7 +52,7 @@ struct qdf_flex_mem_pool {
 	qdf_list_t seg_list;
 	struct qdf_spinlock lock;
 	uint16_t reduction_limit;
-	uint16_t item_size;
+	uint32_t item_size;
 };
 
 /**