Added driver to control the external power output

This PR adds support to control the external power output from controllers like nice!nano, nRFMicro etc

I have implemented based on my understanding of Pete suggestion on this feature.

Testing done:

    Tested by enabling and disabling the ext_power from application and verified
    Verified the application does not crash with boards that does not have ext_power support
    Note:
    I did not test this in nice!nano since I don't have the boards. Will get help from others once the behavior PR is up

Next Steps:

    Create a behavior PR to control enable/disable ext_power

1 files changed, 9 insertions, 0 deletions

diff --git a/app/src/main.c b/app/src/main.c
index dca923e..0551356 100644
--- a/app/src/main.c
+++ b/app/src/main.c
@@ -15,16 +15,25 @@ LOG_MODULE_REGISTER(zmk, CONFIG_ZMK_LOG_LEVEL);
 #include <zmk/matrix.h>
 #include <zmk/kscan.h>
 #include <zmk/display.h>
+#include <drivers/ext_power.h>
 
 #define ZMK_KSCAN_DEV DT_LABEL(ZMK_MATRIX_NODE_ID)
 
 void main(void) {
+    struct device *ext_power;
     LOG_INF("Welcome to ZMK!\n");
 
     if (zmk_kscan_init(ZMK_KSCAN_DEV) != 0) {
         return;
     }
 
+    // Enable the external VCC output
+    ext_power = device_get_binding("EXT_POWER");
+    if (ext_power != NULL) {
+        const struct ext_power_api *ext_power_api = ext_power->driver_api;
+        ext_power_api->enable(ext_power);
+    }
+
 #ifdef CONFIG_ZMK_DISPLAY
     zmk_display_init();