usb_cdc: Only call bootloader_request() if CONFIG_HAVE_BOOTLOADER_REQUEST

Check for the build symbol prior to calling bootloader_request().
Enable the build symbol on rp2040, atsam, and atsamd chips.

This also enables serial bootloader requsts on rp2040, atsam, and
atsamd.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

src/rp2040/Kconfig

@@ -14,6 +14,7 @@ config RP2040_SELECT
     select HAVE_CHIPID
     select HAVE_GPIO_HARD_PWM
     select HAVE_STEPPER_BOTH_EDGE
+    select HAVE_BOOTLOADER_REQUEST
 
 config BOARD_DIRECTORY
     string