Heather Locklear and her rock-star husband Richie Sambora are splitting up, the actress's rep, Cece Yorke, tells PEOPLE. "After 11 years of marriage Heather Locklear has filed for divorce from Richie Sambora," says the rep. "This is a private matter and there will be no further comment at this time." In paperwork filed Thursday in Los Angeles County Superior Court, Locklear requests physical custody of the couple's 8-year-old daughter, Ava Elizabeth, with visitation rights for Sambora. The actress cites "irreconcilable differences" as the reason for the split. According to the divorce petition, the couple signed a prenuptial agreement that determines...