firmware_ECUsbPorts: Defining config details to run the test

Currently this test is NA. Defining 'usb' & 'smart_usb_charge' in
ec_capability and adding usb port name 'EN_USB_A_5V' as 'custom_usb_enable_names'
variable in config/dragonegg.py file.

Bug=None
Branch=None
TEST= Ran the firmware_ECUsbPorts test with the CL. Test is running & passing without
any issue. Also verified that USB port was powered on/off while the test ran.

Change-Id: I634193ced00ad886ba96d67033aab9ae279808c5
Signed-off-by: Sathees Velayutham <satheesx.velayutham@intel.com>
Reviewed-on: https://chromium-review.googlesource.com/1341809
Commit-Ready: SatheesX Velayutham <satheesx.velayutham@intel.com>
Tested-by: SatheesX Velayutham <satheesx.velayutham@intel.com>
Reviewed-by: Naresh Solanki <naresh.solanki@intel.com>
Reviewed-by: Jett Rink <jettrink@chromium.org>
diff --git a/server/cros/faft/config/dragonegg.py b/server/cros/faft/config/dragonegg.py
index 0953673..00f9b76 100644
--- a/server/cros/faft/config/dragonegg.py
+++ b/server/cros/faft/config/dragonegg.py
@@ -8,9 +8,10 @@
     """FAFT config values for Dragonegg."""
     chrome_ec = True
     ec_capability = ['battery', 'charging',
-                     'keyboard', 'lid', 'x86' ]
+                     'keyboard', 'lid', 'x86', 'usb', 'smart_usb_charge']
     firmware_screen = 15
     wp_voltage = 'pp3300'
     spi_voltage = 'pp3300'
     servo_prog_state_delay = 10
     dark_resume_capable = True
+    custom_usb_enable_names = ['EN_USB_A_5V']