update usb_serial example

Author: kiffie

examples/usb_serial/Cargo.lock

@@ -15,7 +15,7 @@ mips-mcu = { version = "0.3.0", features = ["critical-section-single-core"] }
 mips-rt = "0.3.6"
 mips-mcu-alloc = "0.6.2"
 embedded-hal = "1.0.0"
-pic32-hal = { version = "0.12.1", features = ["usb-device"] }
+pic32-hal = { version = "0.13.0", features = ["usb-device"] }
 panic-halt = "1.0.0"
 usb-device = { version = "0.3.2", features = ["control-buffer-256"] }
 usbd-serial = "0.2.2"
@@ -25,6 +25,3 @@ pic32-config-sector = "0.3.0"
 opt-level = 3
 lto = true
 debug = true
-
-[patch.crates-io]
-pic32-hal = { git = "https://github.com/kiffie/pic32-rs.git", branch = "usb03"}