The SPL_BINARY was no longer being set properly after the machine name change
from imx8qmmek to imx8qm-mek, resulting in the following build break for
imx-boot:
```
| make[1]: *** No rule to make target 'u-boot-spl.bin', needed by 'flash_spl'. Stop.
```
The override of the machine name is of course redundant here, so just
drop the override.
Signed-off-by: Tom Hochstein <tom.hochstein@nxp.com>
UBOOT_MAKE_TARGET = \
"${@bb.utils.contains('MACHINE_FEATURES', 'optee', '', \
'u-boot.bin', d)}"
-SPL_BINARY_imx8qmmek = \
+SPL_BINARY = \
"${@bb.utils.contains('MACHINE_FEATURES', 'optee', 'spl/u-boot-spl.bin', \
'', d)}"
UBOOT_SUFFIX = "bin"