atmel-samd: reduce inlining on constrained boards again

pewpew10, pirkey_m0, and uchip all fit now.  However, pirkey_m0
now has just 76 bytes flash available.

ports/atmel-samd/boards/pewpew10/mpconfigboard.mk

@@ -23,3 +23,5 @@ CIRCUITPY_USB_MIDI = 0
 SUPEROPT_GC = 0
 
 FROZEN_MPY_DIRS += $(TOP)/frozen/pew-pewpew-standalone-10.x
+
+CFLAGS_BOARD = --param inline-unit-growth=15 --param max-inline-insns-auto=15

ports/atmel-samd/boards/pirkey_m0/mpconfigboard.mk

@@ -30,4 +30,4 @@ FROZEN_MPY_DIRS += $(TOP)/frozen/Adafruit_CircuitPython_DotStar
 FROZEN_MPY_DIRS += $(TOP)/frozen/Adafruit_CircuitPython_HID
 FROZEN_MPY_DIRS += $(TOP)/frozen/Adafruit_CircuitPython_IRRemote
 
-CFLAGS_BOARD = --param inline-unit-growth=15 --param max-inline-insns-auto=20
+CFLAGS_BOARD = --param inline-unit-growth=15 --param max-inline-insns-auto=12

ports/atmel-samd/boards/uchip/mpconfigboard.mk

@@ -10,3 +10,5 @@ CHIP_FAMILY = samd21
 INTERNAL_FLASH_FILESYSTEM = 1
 LONGINT_IMPL = NONE
 CIRCUITPY_SMALL_BUILD = 1
+
+CFLAGS_BOARD = --param inline-unit-growth=15 --param max-inline-insns-auto=20