cml1.bbclass: use consistent make flags for menuconfig

cml1.bbclass: use consistent make flags for menuconfig

The class called 'make menuconfig' without any of the make variables and
options set in EXTRA_OEMAKE, resulting in a quite different build
environment than actually intended.

For the kernel.bbclass this was fixed in commit 8c616bc0 ("kernel: Use
consistent make flags for menuconfig") by appending ${EXTRA_OEMAKE} to
KCONFIG_CONFIG_COMMAND.

Instead of fixing this individually for additional recipes, we simply
include ${EXTRA_OEMAKE} in KCONFIG_CONFIG_COMMAND by default.

For most class users, this change is directly visible in the generated
.config file:

* For barebox and u-boot, the CONFIG_GCC_VERSION erroneously reflected
  the host GCC version before where it now correctly reflects the target
  toolchain's GCC.

* For u-boot, also the "Compiler: " line at the beginning of the .config
  now prints the target toolchain instead of the host ones.

* The kernel had this already set.

* busybox did not produce any difference.

Note that these projects might base some compile-time decisions on e.g.
the actual compiler version used. Having the wrong one in the
menuconfig-generated .config affects at least the visibility and
consistency.

Reported-by: Ulrich Ölmann <u.oelmann@pengutronix.de>
Signed-off-by: Enrico Jörns <ejo@pengutronix.de>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>