package/uhd: fix typo
Replace ENABLE_DPKD by ENABLE_DPDK to fix the following error:
Manually-specified variables were not used by the project:
BUILD_DOC
BUILD_DOCS
BUILD_EXAMPLE
BUILD_EXAMPLES
BUILD_TEST
BUILD_TESTING
BUILD_TESTS
ENABLE_DPKD
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>