support/misc/toolchainfile.cmake.in: use TARGET_LDFLAGS for shared and module libraries

With cmake packages, we are only using TARGET_LDFLAGS for executables
and not for shared libraries.

This patch adds CMAKE_SHARED_LINKER_FLAGS and
CMAKE_MODULE_LINKER_FLAGS to the cmake toolchain file so that
buildroot TARGET_LDFLAGS are used for shared and module libraries.

Signed-off-by: Damien Thébault <damien.thebault@vitec.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>