Both variables were used (with the same value) interchangeably
throughout CMake files and per the discussion in GH issue,
ZEPHYR_BASE is preferred.
Also add a comment with explanation of one vs. the other.
Tested by building hello_world for several boards ensuring no errors.
Fixes#7173.
Signed-off-by: Alex Tereschenko <alext.mkrs@gmail.com>
The original em7d, em9d and em11d are different configurations of
em_starterkit. They have the same peripherals, e.g. uart, spi, gpio
, ddr. The differences of them are in arc core configurations, interrupt
number assignment.
So em7d, em9d and em11d can be viewed in the same SoC family or SoC
series.
Referring other arch's implementation, this commit merges em7d, em9d
and em11d into the same SoC, named snps_emsk. This will eliminate
unnecessary duplication and make it easier for future maintainment.
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>