package/ifplugd: add patch to fix musl build error

The musl C library does not define type names such as `__uint32_t`. Instead we
use the integer types declared in the ISO C standard header file <stdint.h>.

Signed-off-by: Jörg Krause <joerg.krause@embedded.rocks>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>