nrf: support disabling SPIM3

SPIM3 is faster than all other SPI blocks, and is capable of generating
a 32 MHz clock.  However, it cannot be used at the same time as the BLE
radio without dedicating an additional 8 kB of RAM to it.

Therefore, some boards may want to disable this.  Support pre-defining
NRFX_SPIM3_ENABLED on the command line to disable it on some bords.

Signed-off-by: Sean Cross <[email protected]>

Author: xobs

ports/nrf/nrfx_config.h

@@ -41,12 +41,14 @@
 #define NRFX_SPIM1_ENABLED 1
 #endif
 #define NRFX_SPIM2_ENABLED 1
+#ifndef NRFX_SPIM3_ENABLED
 #if defined(NRF52840_XXAA) || defined(NRF52833_XXAA)
     #define NRFX_SPIM_EXTENDED_ENABLED 1
     #define NRFX_SPIM3_ENABLED 1
 #elif CIRCUITPY_NRF_NUM_I2C == 2
     #define NRFX_SPIM3_ENABLED 0
 #endif
+#endif
 
 
 #define NRFX_SPIM_DEFAULT_CONFIG_IRQ_PRIORITY 7