[Keyboard] KBD75 refactor (#6755)

* convert codebase to #pragma once

* fix file includes

- quantum.h is included at keyboard level, redundant at revision level
- keyboard-level path is accessible at revision level, remove relative pathing

* duplicate common layout macros from rev1 to rev2

Add the layout macros supported by both rev1 and rev2 to rev2.h directly, which exposes these layouts to QMK Configurator.

* enable community layout support (75_ansi, 75_iso)

* add LAYOUT_75_iso layout data

It needs its own tree because its keys are in a different order from LAYOUT_iso_1u even though the physical layout is the same.

* minimize rules.mk files (use QMK defaults)

* use atmel-dfu bootloader rule

* fix typo on rev1 info.json

keyboards/kbdfans/kbd75/rev2/rules.mk

@@ -1,44 +1,8 @@
 # MCU name
 MCU = atmega32u4
 
-# Processor frequency.
-#     This will define a symbol, F_CPU, in all source code files equal to the
-#     processor frequency in Hz. You can then use this symbol in your source code to
-#     calculate timings. Do NOT tack on a 'UL' at the end, this will be done
-#     automatically to create a 32-bit value in your source code.
-#
-#     This will be an integer division of F_USB below, as it is sourced by
-#     F_USB after it has run through any CPU prescalers. Note that this value
-#     does not *change* the processor frequency - it should merely be updated to
-#     reflect the processor speed set externally so that the code can use accurate
-#     software delays.
-F_CPU = 16000000
-
-#
-# LUFA specific
-#
-# Target architecture (see library "Board Types" documentation).
-ARCH = AVR8
-
-# Input clock frequency.
-#     This will define a symbol, F_USB, in all source code files equal to the
-#     input clock frequency (before any prescaling is performed) in Hz. This value may
-#     differ from F_CPU if prescaling is used on the latter, and is required as the
-#     raw input clock is fed directly to the PLL sections of the AVR for high speed
-#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
-#     at the end, this will be done automatically to create a 32-bit value in your
-#     source code.
-#
-#     If no clock division is performed on the input clock inside the AVR (via the
-#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
-F_USB = $(F_CPU)
-
-# Interrupt driven control endpoint task(+60)
-OPT_DEFS += -DINTERRUPT_CONTROL_ENDPOINT
-
-
-# Boot Section Size in *bytes*
-OPT_DEFS += -DBOOTLOADER_SIZE=4096
+# Bootloader selection
+BOOTLOADER = atmel-dfu
 
 
 # Build Options
@@ -53,4 +17,6 @@ SLEEP_LED_ENABLE = no  # Breathing sleep LED during USB suspend
 NKRO_ENABLE = yes		# USB Nkey Rollover - if this doesn't work, see here: https://github.com/tmk/tmk_keyboard/wiki/FAQ#nkro-doesnt-work
 BACKLIGHT_ENABLE = yes  # Enable keyboard backlight functionality
 AUDIO_ENABLE = no
-RGBLIGHT_ENABLE = yes
+RGBLIGHT_ENABLE = yes
+
+LAYOUTS = 75_ansi 75_iso