Use "correct" lock/unlock byte values

This prevents Avrdude 7.1 from throwing a warning that the user is trying to write zeros to unused bits

avr/boards.txt

@@ -47,8 +47,8 @@ menu.bootloader=Bootloader
 328.upload.tool=avrdude
 328.upload.maximum_data_size=2048
 328.bootloader.tool=avrdude
-328.bootloader.unlock_bits=0x3f
-328.bootloader.lock_bits=0x0f
+328.bootloader.unlock_bits=0xff
+328.bootloader.lock_bits=0xcf
 328.build.core=MCUdude_corefiles
 328.build.board=AVR_ATmega328
 328.build.bootloader_led=B5
@@ -256,8 +256,8 @@ menu.bootloader=Bootloader
 168.upload.maximum_size=15872
 168.upload.maximum_data_size=1024
 168.bootloader.tool=avrdude
-168.bootloader.unlock_bits=0x3f
-168.bootloader.lock_bits=0x0f
+168.bootloader.unlock_bits=0xff
+168.bootloader.lock_bits=0xcf
 168.build.core=MCUdude_corefiles
 168.build.board=AVR_ATmega168
 168.build.bootloader_led=B5
@@ -453,8 +453,8 @@ menu.bootloader=Bootloader
 88.upload.tool=avrdude
 88.upload.maximum_data_size=1024
 88.bootloader.tool=avrdude
-88.bootloader.unlock_bits=0x3f
-88.bootloader.lock_bits=0x0f
+88.bootloader.unlock_bits=0xff
+88.bootloader.lock_bits=0xcf
 88.build.core=MCUdude_corefiles
 88.build.board=AVR_ATmega88
 88.build.bootloader_led=B5
@@ -652,7 +652,7 @@ menu.bootloader=Bootloader
 48.upload.maximum_size=4096
 48.upload.maximum_data_size=512
 48.bootloader.tool=avrdude
-48.bootloader.unlock_bits=0x3f
+48.bootloader.unlock_bits=0xff
 48.bootloader.lock_bits=0x3f
 48.bootloader.extended_fuses=0xff
 48.build.core=MCUdude_corefiles
@@ -824,8 +824,8 @@ menu.bootloader=Bootloader
 8.upload.tool=avrdude
 8.upload.maximum_data_size=1024
 8.bootloader.tool=avrdude
-8.bootloader.unlock_bits=0x3f
-8.bootloader.lock_bits=0x0f
+8.bootloader.unlock_bits=0xff
+8.bootloader.lock_bits=0xcf
 8.bootloader.low_fuses=0b{bootloader.bod_bits}{bootloader.sut_cksel_bits}
 8.bootloader.high_fuses=0b110{bootloader.ckopt_bit}{bootloader.eesave_bit}10{bootloader.bootrst_bit}
 8.build.core=MCUdude_corefiles