cmake: mwdt assembler option for imacros

Add the -imacros property for assembler language to compensate
for changes introduced in PR zephyrproject-rtos#84800.

Signed-off-by: Björn Bergman <[email protected]>

Author: bjorniuppsala

cmake/compiler/arcmwdt/compiler_flags.cmake

@@ -165,6 +165,9 @@ set_compiler_property(PROPERTY coverage "")
 # mwdt compiler flags for imacros. The specific header must be appended by user.
 set_compiler_property(PROPERTY imacros -imacros)
 
+# assembler compiler flags for imacros. The specific header must be appended by user.
+set_property(TARGET asm PROPERTY imacros -imacros)
+
 # Security canaries.
 #no support of -mstack-protector-guard=global"
 set_compiler_property(PROPERTY security_canaries -fstack-protector)