app: aboot: Use HOME button to enter fastboot mode

In lk2nd KEY_HOME keycode is used as a generic "go into fastboot" button
that doesn't carry any extra meaning in the menus. As original caf lk
doesn't use this key for anything modern we are safe to reassign it's
meaning to "fastboot" in aboot.

(cherry picked from commit 0bbd2eb)

app/aboot/aboot.c

@@ -5593,10 +5593,10 @@ void aboot_init(const struct app_descriptor *app)
 	}
 	if (!boot_into_fastboot)
 	{
-		if (keys_get_state(KEY_HOME) || keys_get_state(KEY_VOLUMEUP))
+		if (keys_get_state(KEY_VOLUMEUP))
 			boot_into_recovery = 1;
 		if (!boot_into_recovery &&
-			(keys_get_state(KEY_BACK) || keys_get_state(KEY_VOLUMEDOWN)))
+			(keys_get_state(KEY_HOME) || keys_get_state(KEY_BACK) || keys_get_state(KEY_VOLUMEDOWN)))
 			boot_into_fastboot = true;
 	}
 	#if NO_KEYPAD_DRIVER