galp6: Fix USB power

The schematics incorrectly show the pin as `USB_PWR_EN#`. There is a
comment on the port side clarifying that it is actually active high.

Signed-off-by: Tim Crawford <tcrawford@system76.com>

src/board/system76/galp6/board.c

@@ -16,8 +16,6 @@ void board_init(void) {
     // Enable wireless
     gpio_set(&WLAN_EN, true);
     gpio_set(&WLAN_PWR_EN, true);
-    // Enable USB power
-    gpio_set(&USB_PWR_EN_N, false);
     // Assert SMI# and SWI#
     gpio_set(&SMI_N, true);
     gpio_set(&SWI_N, true);