LSM6DS3TR-C support (#3593)

* started work on pulling in the unphone library and dependencies, to do e.g. power switch management and etc.; currently failing at Adafruit_ImageReader

* now compiles with unphoneLibrary included

* successfully pulled in unphone library to manage power switch and init vibe motor and etc.
doesnt print to serial tho...

* simplified the build a bit; when doing meshtastic do not depend on the MCCI lora libs etc., then also no need to config them via build flags

* version that doesnt trigger brownout

* cleaned up initVariant a little

* note re. GPS

* back to mesh upstream version

* this time we're back to mesh upstream version

* getting LSM6DS3TRC driver installed

* shake to wake works, set threshold quite low may need increasing

* whats the crack with these end of file changes?

* paramatize the wake threshold

* try to get the PR to just include real changes

* got the right config item and also not giving compiler messages

* moved the lib_deps for the LSM6DS3TRC driver from our variant platformio.ini to the main one in root so all boards have it

* stuupid error #define-ing

---------

Co-authored-by: Hamish Cunningham <hamish@gate.ac.uk>
Co-authored-by: Ben Meadors <benmmeadors@gmail.com>

variants/unphone/variant.h

@@ -53,6 +53,8 @@
 #define I2C_SDA 3 // I2C pins for this board
 #define I2C_SCL 4
 
+#define LSM6DS3_WAKE_THRESH 5 // higher values reduce the sensitivity of the wake threshold
+
 // ratio of voltage divider = 3.20 (R1=100k, R2=220k)
 // #define ADC_MULTIPLIER 3.2