Use generic chip type identifiers

[TG9541]

Device type identifiers can be misleading, especially when generic properties that depend more on density than on anything else have to be configured.

Use the following identifiers in the core source files:

        ; Chip type (set of peripheral addresses and features)
        STM8L_LOD        = 051  ; STM8L Low Density
        STM8L_MHD        = 152  ; STM8L Medium and High Density
        STM8S_LOD        = 103  ; STM8S Low Density
        STM8S_MED        = 105  ; STM8S Medium Density
        STM8S_HID        = 207  ; STM8S High Density