class/useflags: Remove MACHINE_USE_ for sdk, native, sdk-cross recipes
class/useflags: Remove MACHINE_USE_ for sdk, native, sdk-cross recipes

MACHINE_USE_ flags must not be used in sdk, native and sdk-cross recipes so
delete them before setting the USE_ flags.

Fixes bug where EXTRA_ARCH was set to ".${MACHINE}" in useflags.oeclass when a
MACHINE_USE flag was set in a sdk-cross recipe. In this case of sdk-cross:gcc
and use of MACHINE_USE_toolchain_min_kernel_machine.

Signed-off-by: Esben Haabendal <c5ba3f1141bb30a64dd6c7e6726a53a85adc9442@prevas.dk>

hundeboll/core,sknsean/core,sknsean/core,sknsean/core,diorcety/oe-lite-core,hundeboll/core,sknsean/core,sknsean/core,diorcety/oe-lite-core,hundeboll/core,hundeboll/core