add different rx_len/tx_len use case

Author: ithinuel

hal/rfcs/0000-spi-overhaul.md

@@ -35,6 +35,7 @@ In order to provide a meaningful API, this RFC will consider the following use c
 - <details><summary>SPI Master: <a href="https://github.com/ARMmbed/stm-spirit1-rf-driver">stm-spirit1-rf</a> (Sub-1 GHz RF based on the SPSGRF-868 Module)</summary><ul><li>initial freq : 10MHz</li><li>clock polarity: low</li><li>clock phase : first edge</li><li>word size : 8bits</li><li>Chip select : manual (could it be automated ? There seem to be some special delays)</li></ul></details> 
 - <details><summary>SPI Master: <a href="https://github.com/ARMmbed/ble-x-nucleo-idb0xa1">ble-x-nucleo-idb0xa1</a> (BLE module)</summary><ul><li>initial freq : 8MHz</li><li>clock polarity: low</li><li>clock phase : first edge</li><li>word size : 8bits</li><li>Chip select : manual (could be automated as it is sending/receiving byte by byte)</li></ul></details>
 - <details><summary>SPI Master: <a href="https://os.mbed.com/cookbook/SPI-communication-with-external-ADC-MCP3">ADC</a></summary><ul><li>initial freq  : 1MHz</li><li>clock polarity: low</li><li>clock phase : first edge</li><li>word size : 7bits</li><li>Chip select : manual (could it be automated ? There seem to be some special delays)</li><li>The comment in the code is confusing as it refers to "high steady state" and "second edge capture".</li></ul></details>
+- <details><summary>SPI Master: <a href="https://os.mbed.com/users/AppNearMe/code/AppNearMe_MuNFC_PN532">AppNearMe MuNFC PN532</a></summary><ul><li>Initial freq: 5MHz</li><li>clock polarity: Idle High</li><li>clock phase: Data on second edge (aka active to idle edge)</li><li>word size: 8bits</li><li>chip select: manual</li><li>use of different tx_len & rx_len + some skip offset.</li></ul></details>
 
 ### Other use cases
 - SPI Slave