The "-s -w" flags in GO_PKG_LDFLAGS tells the Go compiler to strip the
binaries it produces. Since the default Go package build process will
strip binaries when CONFIG_USE_STRIP or CONFIG_USE_SSTRIP are selected,
these flags are unnecessary.

When CONFIG_NO_STRIP is selected, these flags override the user's
intention of building unstripped packages.

This removes these flags for all relevant packages.

Signed-off-by: Jeffery To <jeffery.to@gmail.com>