fix(build): Fix nano printf pulling in floats

Signed-off-by: Rahix <rahix@rahix.de>

card10-cross.ini

@@ -6,7 +6,7 @@ strip = 'arm-none-eabi-strip'
 [properties]
 c_args      = ['-mthumb', '-mcpu=cortex-m4', '-mfloat-abi=hard', '-mfpu=fpv4-sp-d16', '-Wa,-mimplicit-it=thumb', '-ffunction-sections', '-fdata-sections', '-fsingle-precision-constant', '-fno-isolate-erroneous-paths-dereference']
 
-c_link_args = ['-mthumb', '-mcpu=cortex-m4', '-mfloat-abi=hard', '-mfpu=fpv4-sp-d16', '-Wl,--start-group', '-lc', '-lnosys', '-Wl,--end-group', '--specs=nano.specs', '-u _printf_float']
+c_link_args = ['-mthumb', '-mcpu=cortex-m4', '-mfloat-abi=hard', '-mfpu=fpv4-sp-d16', '-Wl,--start-group', '-lc', '-lnosys', '-Wl,--end-group', '--specs=nano.specs']
 
 target_defs = ['-DTARGET=32665', '-DTARGET_REV=0x4131', '-DBOARD_CARD10=1']