kernel: mempool: fix race condition in rt_mp_alloc

When thread wake up from waiting for memory, there is a chance that
there is no memory available in high pressure. So use a loop to check
again. Otherwise, there will be a NULL reference.

Ls1b

[BSP]BM9BF618S:fix timer initialization issue.

correct spelling error

clear old groups in template.uvproj.

[DeviceDrivers] Add more SPI drivers. 

Move PNG_NO_WRITE_SUPPORTED outside of RT_USING_NEWLIB. #197

[BSP] tm4c129x Add EMAC/PHY driver

1. Resize RT_LWIP_SEG_NUM drom 8 to 12
2. modify gcc compile switch, using C99

1. Add ETH MAC driver using DMA for Tx and Rx lwip pBuf.
2. Modify the tivaware emac library to fix the bug that PHY read is not stable when sysclk is 120MHz
3. In PHY IRQ handler, insert a dummy reading (REG_BMSR) before read PHY_STS to force update STS register.

This reverts commit 666d1298.

1. Add ETH MAC driver using DMA for Tx and Rx lwip pBuf.
2. Modify the tivaware emac library to fix the bug that PHY read is not stable when sysclk is 120MHz
3. In PHY IRQ handler, insert a dummy reading (REG_BMSR) before read PHY_STS to force update STS register.