Update cellular platform header APIs

[chinglee-iot]

Description

Cellular interface makes use of the platform header to abstract FreeRTOS dependency.

In this PR:

• Move the following FreeRTOS functions and data structure to platform and add CELLULAR_CONFIG_PLATFORM_FREERTOS for backward compatibility. Default to 1 to define the following macros.

  #define PlatformQueueHandle_t    QueueHandle_t
  #define PlatformEventBits_t      EventBits_t
  #define PlatformBaseType_t       BaseType_t
  #define PlatformTickType_t       TickType_t
  #define platformTRUE             pdTRUE
  #define platformFALSE            pdFALSE
  #define platformPASS             pdPASS
  #define platformFAIL             pdFAIL
  #define platformMAX_DELAY        portMAX_DELAY
  #define PlatformQueue_Create     xQueueCreate
  #define PlatformQueue_Send       xQueueSend
  #define PlatformQueue_Receive    xQueueReceive
  #define PlatformQueue_Delete     vQueueDelete

• Add CELLULAR_CONFIG_ASSERT config. Default value is configASSERT
• Remove critical section dependency. The common layer function is not thread safe.

Test Steps

N/A

Checklist:

• [x] I have tested my changes. No regression in existing tests.
• [] I have modified and/or added unit-tests to cover the code changes in this Pull Request.

Related Issue

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.