Factor out spi lib

PUBLISHED_FROM=49273258bae6da75b5cbf7013dd9611ee2cf845c

Author: dimonomid

mos.yml

@@ -18,6 +18,7 @@ libs:
   - origin: https://github.com/mongoose-os-libs/rpc-service-i2c
   - origin: https://github.com/mongoose-os-libs/rpc-service-ota
   - origin: https://github.com/mongoose-os-libs/rpc-uart
+  - origin: https://github.com/mongoose-os-libs/spi
   - origin: https://github.com/mongoose-os-libs/vfs-dev-spi-flash
 
     # libs necessary for the current app
@@ -27,7 +28,6 @@ config_schema:
   - ["i2c.enable", true]
 build_vars:
   MGOS_ENABLE_I2C: 1
-  MGOS_ENABLE_SPI: 1
 
 tags:
   - js