refactor(lib/smc): Use SET_MEMBER_RSI for RSI header

The smc-rsi.h header is refactored to use SET_MEMBER_RSI.
The patch also removes some unneeded header inclusions.

Signed-off-by: Yousuf A <yousuf.sait@arm.com>
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
Change-Id: Id1a8315c3c30d79a83917bec1aa296f35b132ea0