non-DMA SPI working; adding this now for testing; will continue with DMA

Also, fixed pin mappings for rev B Metro M4: swap PA12 and PA13 on SPI 2x3 header swap A3 and A5 Comment out all frozen modules in CPX again to make room while waiting for SPI flash.

Author: dhalbert

ports/atmel-samd/Makefile

@@ -172,6 +172,7 @@ SRC_ASF := \
 hal/src/hal_i2c_m_sync.c \
 hal/src/hal_io.c \
 hal/src/hal_sleep.c \
+hal/src/hal_spi_m_sync.c \
 hal/src/hal_timer.c \
 hal/src/hal_usb_device.c \
 hpl/core/hpl_init.c \
@@ -252,6 +253,7 @@ SRC_COMMON_HAL = \
 board/__init__.c \
 busio/__init__.c \
 busio/I2C.c \
+busio/SPI.c \
 digitalio/__init__.c \
 digitalio/DigitalInOut.c \
 microcontroller/__init__.c \
@@ -267,7 +269,6 @@ SRC_COMMON_HAL = \
 audiobusio/PDMIn.c \
 audioio/__init__.c \
 audioio/AudioOut.c \
-busio/SPI.c \
 busio/UART.c \
 neopixel_write/__init__.c \
 nvm/__init__.c \