./configure script detects if serdisplib is built on non-linux build
host and disables framebuffer driver. It blocks touchscreen_tool
compilation. This detection is not required on cross-compile build
so it is disabled via ac_cv_build=$(GNU_TARGET_NAME) in Makefile

Signed-off-by: Sergey V. Lobanov <sergey@lobanov.in>

Use standard PKG_INSTALL. Added patch to fix compilation with it.

Use PKG_INSTALL_DIR as a result.

Added PKG_BUILD_PARALLEL for faster compilation.

Fixed license information.

Add build depends for libusb as it is needed for compilation.

Various small cleanups.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

Signed-off-by: Daniel Golle <daniel@makrotopia.org>