kl27z: Increase DAP_PACKET_COUNT to 8.

[microbit-carlos]

This is to match the same DAP queue length for micro:bit V2.00, to the same length as configured in V2.2x.

DAPLink/source/hic_hal/nordic/nrf52820/DAP_config.h

Lines 94 to 98 in 82dc31d

	/// Maximum Package Buffers for Command and Response data.
	/// This configuration settings is used to optimize the communication performance with the
	/// debugger and depends on the USB peripheral. For devices with limited RAM or USB buffer the
	/// setting can be reduced (valid range is 1 .. 255).
	#define DAP_PACKET_COUNT 8U ///< Specifies number of packets buffered.

This might not be needed in the end, so leaving as a draft PR first. I'm looking into speeding up WebUSB flashing, and having a longer DAP queue seems to help, although maybe not by that much.