Kconfig: Support selecting optional features on chips with small flash size

Add a new HAVE_LIMITED_CODE_SIZE symbol that enables a menu to select
optional features.  This symbol is enabled on chips with small build
sizes.

Replace the HAVE_GPIO_BITBANGING with four new symbols:
WANT_GPIO_BITBANGING, WANT_DISPLAYS, WANT_SENSORS, WANT_SOFTWARE_SPI,
and WANT_SOFTWARE_I2C.  This allows users a little more flexibility
when selecting features they need.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

src/ar100/Kconfig

@@ -7,8 +7,8 @@ config AR100_SELECT
     default y
     select HAVE_GPIO
     select HAVE_GPIO_SPI
-    select HAVE_GPIO_BITBANGING
     select HAVE_STEPPER_BOTH_EDGE
+    select HAVE_LIMITED_CODE_SIZE
 
 config BOARD_DIRECTORY
     string

src/ar100/Makefile

@@ -19,12 +19,6 @@ src-y += ar100/main.c ar100/gpio.c ar100/serial.c
 src-y += ar100/util.c ar100/timer.c
 src-y += generic/crc16_ccitt.c generic/timer_irq.c
 
-# Remove files that are not needed to save space
-src-y := $(filter-out lcd_hd44780.c,$(src-y))
-src-y := $(filter-out lcd_st7920.c,$(src-y))
-src-y := $(filter-out sensor_angle.c,$(src-y))
-src-y := $(filter-out thermocouple.c,$(src-y))
-
 OBJS_klipper.elf += $(OUT)lib/ar100/start.o
 OBJS_klipper.elf += $(OUT)lib/ar100/runtime.o