Staging: poch: Update TODO list

Update TODO list.
Signed-off-by: NVijay Kumar <vijaykumar@bravegnu.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/staging/poch/README

 TODO:
-	- fix transmit overflows
+	- Rx block size is limited to < 2048, hardware bug?
+	- Group size is limited to < page size, kernel alloc/mmap API issues
+	- fix/workaround cache issues in circular buffer header
+	- test whether Tx is transmitting data from provided buffers
+	- handle device unplug case
+	- handle temperature above threshold
+	- use bus address instead of physical address for DMA
+	- support for snapshot mode
 	- audit userspace interfaces
 	- get reserved major/minor if needed