实现rt_hw_us_delay函数

1. The issue concerns sdmmc library bug (I finally solved) in SD_Init() in the file sdmmc/src/fsl_sd.c:SD_SelectBusTiming()
calls SD_SwitchFunction() which sets block size to 64bytes (512bits).Therefore SD_SetBlockSize(card, FSL_SDMMC_DEFAULT_BLOCK_SIZE)
should be called again before SD_Init() exits.
2. The issue is wrong variable in drv_emac.c:lpc_emac_tx(), and the wrong data length of send packet
to cause the send failure.
Signed-off-by: Nzheng-chow <sernia.zhou@foxmail.com>

[bsp][stm32f429-apollo] Disable the SPI DMA mode. It has some problem when using big data transmission.

[stm32f10x-HAL] Fixed the problem of including functions in RT_ASSERT()|修复了：当屏蔽宏定义RT_DEBUG时，RT_ASSERT()中的函数运行不到

get_week获取的值是0-6.而stm32f4xx_rtc.h中IS_RTC_WEEKDAY中判断的有效值是1-7.当设置日期是周日时，会有问题。