Use libnitrokey directly instead of a static link

[szszszsz]

Use libnitrokey directly to allow to remove unused parts of it by LTO. This would help to save space in Heads.
This is an alternative solution to #2, however this one should be preferred.

The flags below should contain these as well: -ffunction-sections -fdata-sections to make the gc-sections work.

nitrokey-storage-cli/src/Makefile

Lines 5 to 9 in 4712175

	STATIC_CFLAGS=-frandom-seed=0x12345678 -ffile-prefix-map=$(pwd)=nkstorecli -Wl,-gc-sections
	STATIC_INCLUDES=-I$(INSTALL)/../crossgcc/x86_64-linux-musl/include
	STATIC_LIBS=-L$(INSTALL)/lib -L$(INSTALL)/../crossgcc/x86_64-linux-musl/lib64 -lnitrokey -lhidapi-libusb -lusb-1.0 -lstdc++