Add event_loop_group struct import

Author: lauzadis

aws-crt-kotlin/native/src/aws/sdk/kotlin/crt/io/EventLoopGroupNative.kt

@@ -9,6 +9,7 @@ import aws.sdk.kotlin.crt.*
 import aws.sdk.kotlin.crt.Allocator
 import aws.sdk.kotlin.crt.util.ShutdownChannel
 import aws.sdk.kotlin.crt.util.shutdownChannel
+import cnames.structs.aws_event_loop_group
 import kotlinx.cinterop.*
 import libcrt.*