#409 Please add support for Atmel MCU: SAMD21G18AU

[Yanbing Yu]

Please add support for Atmel MCU: SAMD21G18AU, which is a WLCSP package form of SAMD21G18A.

According to Atmel errata sheet: http://ww1.microchip.com/downloads/en/DeviceDoc/SAM_D21_%20DA1_Family_Silicon_Errata_DS80000760E.pdf, new entries shall be added into the array of samd21_parts[], as shown below the diff scripts, which has been verified with our own development board.

diff --git a/src/flash/nor/at91samd.c b/src/flash/nor/at91samd.c
index 36298f19d..a91cc5012 100644
--- a/src/flash/nor/at91samd.c
+++ b/src/flash/nor/at91samd.c
@@ -157,6 +157,8 @@ static const struct samd_part samd21_parts[] = {
        { 0xC, "SAMD21E16A", 64, 8 },
        { 0xD, "SAMD21E15A", 32, 4 },
        { 0xE, "SAMD21E14A", 16, 2 },

+       { 0xF, "SAMD21G18AU", 256, 32 },        //YYU: samd21g18au <-- wlcsp of samd21g18a
+       { 0x10, "SAMD21G17AU", 128, 16 },       //YYU: samd21g17au <-- wlcsp of samd21g17a

     /* SAMR21 parts have integrated SAMD21 with a radio */
        { 0x18, "SAMR21G19A", 256, 32 }, /* with 512k of serial flash */