Remove plat_match_rotpk reference

This function was removed long ago.  Remove remaining
pragma reference.

Change-Id: I66c556863d47dc17d2ffdc6c23aa524df6aade80
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>

plat/arm/board/common/board_arm_trusted_boot.c

@@ -12,7 +12,6 @@
 #include <tbbr_oid.h>
 
 /* Weak definition may be overridden in specific platform */
-#pragma weak plat_match_rotpk
 #pragma weak plat_get_nv_ctr
 #pragma weak plat_set_nv_ctr