Add LFCSP-56-1EP_8x8mm_P0.5mm_EP6.6x6.6mm

Hi there,

added LFCSP-56-1EP_8x8mm_P0.5mm_EP6.45x6.45mm w and w/o theremal vias. The footprint was created with the script package kicad-footprint-generator!561 (merged)

EP is a little bit smaller to ensure the minimum clearance of 0.25 mm. Maybe the script has to be tuned.

Package: https://www.analog.com/media/en/package-pcb-resources/package/pkg_pdf/lfcspcp/cp_56_9.pdf Application Note: https://www.analog.com/media/en/technical-documentation/application-notes/AN-772.pdf