target/arm7_9_common: use coherent syntax in struct initialization

target/arm7_9_common: use coherent syntax in struct initialization

While initializing struct command_registration, the field's name "name"
is not specified, thus relying on the fact that it is the first field
declared in the struct and it's initialization value can be listed as
the first one.

Be coherent in the struct initialization and always use the field's
name.

Change-Id: I743457acf7757df4646c9bc4e5ea1a6f9c841516
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/5010
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>
Tested-by: jenkins