Fix Planck and Preonic builds (#5658)

* Planck: Copy contents of Planck rules.mk to each revision

* Planck: Delete Planck rules.mk

* Planck: Concatenate duplicate rules

Concatenate rules that are set and then overridden into one setting.

* Preonic: Copy contents of Preonic rules.mk to each revision

* Preonic: Delete Preonic rules.mk

* Preonic: Concatenate duplicate rules

Concatenate rules that are set and then overridden into one setting.

* Planck: Delete non-specific Bootloader settings from revs. 1 and 2

Deleted BOOTLOADER setting code block, as the checks were only valid for revs. 3-5 and the Planck Light.

Neither Planck rev1 or rev2 set the bootloader via rules.mk, so there's no setting of BOOTLOADER in their rules.mk files.

* Preonic: Fix BOOTLOADER settings code blocks

* Preonic: delete extra blank lines from rules.mk files

* Preonic: delete AVR-type hardware config blocks from rev3

* Update Planck and Preonic readme files

- update Hardware Supported
- update/add Install Examples
- update Docs paragraph

* Enable Bootmagic Lite where it is disabled

Enabled Bootmagic Lite for:

- Planck Light
- Planck revs. 1-5
- Preonic revs. 1 and 2

* Remove `planck_grid` from LAYOUTS rule for all Planck revisions

Community has landed on `ortho_4x12`, which is already set; `planck_grid` is redundant.

keyboards/planck/light/rules.mk

@@ -1,5 +1,36 @@
-MIDI_ENABLE = yes
-AUDIO_ENABLE = yes           # Audio output on port C6
-RGB_MATRIX_ENABLE = yes
+# MCU name
+MCU = at90usb1286
 
-MCU = at90usb1286
+# Bootloader
+#     This definition is optional, and if your keyboard supports multiple bootloaders of
+#     different sizes, comment this out, and the correct address will be loaded
+#     automatically (+60). See bootloader.mk for all options.
+BOOTLOADER = atmel-dfu
+
+# Interrupt driven control endpoint task(+60)
+OPT_DEFS += -DINTERRUPT_CONTROL_ENDPOINT
+
+# Build Options
+#   change to "no" to disable the options, or define them in the Makefile in
+#   the appropriate keymap folder that will get included automatically
+#
+BOOTMAGIC_ENABLE = lite     # Virtual DIP switch configuration(+1000)
+MOUSEKEY_ENABLE = no       # Mouse keys(+4700)
+EXTRAKEY_ENABLE = yes       # Audio control and System control(+450)
+CONSOLE_ENABLE = yes         # Console for debug(+400)
+COMMAND_ENABLE = no        # Commands for debug and configuration
+NKRO_ENABLE = yes            # Nkey Rollover - if this doesn't work, see here: https://github.com/tmk/tmk_keyboard/wiki/FAQ#nkro-doesnt-work
+BACKLIGHT_ENABLE = no      # Enable keyboard backlight functionality
+MIDI_ENABLE = yes           # MIDI controls
+AUDIO_ENABLE = yes           # Audio output on port C6
+UNICODE_ENABLE = no         # Unicode
+BLUETOOTH_ENABLE = no       # Enable Bluetooth with the Adafruit EZ-Key HID
+RGBLIGHT_ENABLE = no        # Enable WS2812 RGB underlight.
+RGB_MATRIX_ENABLE = yes
+API_SYSEX_ENABLE = no
+
+# Do not enable SLEEP_LED_ENABLE. it uses the same timer as BACKLIGHT_ENABLE
+SLEEP_LED_ENABLE = no    # Breathing sleep LED during USB suspend
+
+LAYOUTS = ortho_4x12 planck_mit
+LAYOUTS_HAS_RGB = no