Enable secure timer to generate S-EL1 interrupts
Enable secure timer to generate S-EL1 interrupts

This patch enables secure physical timer during TSP initialisation and
maintains it across power management operations so that a timer
interrupt is generated every half second.

Fixes ARM-software/tf-issues#104
Fixes ARM-software/tf-issues#134

Change-Id: I66c6cfd24bd5e6035ba75ebf0f047e568770a369

idl3r/arm-trusted-firmware,sandrine-bailleux/arm-trusted-firmware,mtk09422/arm-trusted-firmware,yatharth-arm/arm-trusted-firmware,mtk09422/arm-trusted-firmware,athoelke/arm-trusted-firmware,jcastillo-arm/arm-trusted-firmware,davwan01/arm-trusted-firmware,sandrine-bailleux-arm/arm-trusted-firmware,ljerry/arm-trusted-firmware,vchong/arm-trusted-firmware,lsigithub/arm-trusted-firmware_public,athoelke/arm-trusted-firmware,96boards/arm-trusted-firmware,jforissier/arm-trusted-firmware,jforissier/arm-trusted-firmware,davwan01/arm-trusted-firmware,sandrine-bailleux-arm/arm-trusted-firmware,lsigithub/arm-trusted-firmware_public,yatharth-arm/arm-trusted-firmware,achingupta/arm-trusted-firmware,sbranden/arm-trusted-firmware,Leo-Yan/arm-trusted-firmware,achingupta/arm-trusted-firmware,sbranden/arm-trusted-firmware,longsleep/arm-trusted-firmware-pine64,96boards/arm-trusted-firmware,hzhuang1/arm-trusted-firmware,jcastillo-arm/arm-trusted-firmware,robixnai/arm-trusted-firmware,vchong/arm-trusted-firmware,hzhuang1/arm-trusted-firmware,sandrine-bailleux/arm-trusted-firmware,Leo-Yan/arm-trusted-firmware,ljerry/arm-trusted-firmware,idl3r/arm-trusted-firmware,robixnai/arm-trusted-firmware,longsleep/arm-trusted-firmware-pine64