Update CHANGELOG.md for 2.5.0
Update CHANGELOG.md for 2.5.0

Tested-by: Jens Wiklander <7706914404370d7502c27a0eff493dcf491feb51@linaro.org> Juno AArch{32,64}
Tested-by: Jens Wiklander <7706914404370d7502c27a0eff493dcf491feb51@linaro.org> Juno AArch{32,64} pager
Tested-by: Andrew F. Davis <a6dfde0ec5c5124d26ab0cb4f9ab9a758dee1d6f@ti.com>  (ti-dra7xx, ti-am57xx, ti-am43xx)
Tested-by: Igor Opaniuk <ca782e5848fbe7ab0a250faa8ae33b643dd89a09@linaro.org> (RPi3)
Tested-by: Joakim Bech <741f90e2a7f4d9afbad8bd50be20560f4cf38962@linaro.org> (MTK8173)
Tested-by: Jerome Forissier <ced78d268b4c9a0a20a59a9feeebd2ad90da03d3@linaro.org> (hikey 32/64, GP)
Tested-by: Jerome Forissier <ced78d268b4c9a0a20a59a9feeebd2ad90da03d3@linaro.org> (hikey 32/64 pager, GP)
Tested-by: Etienne Carriere <f21bc5b8f3ea1962eb45af359f1abea6578cab94@linaro.org> (b2260, GP)
Tested-by: Etienne Carriere <f21bc5b8f3ea1962eb45af359f1abea6578cab94@linaro.org> (cannes2, GP)
Tested-by: Sumit Garg <0904b466d9452daa97eb086f40b9aaa7e498e972@nxp.com> (ls1021atwr-single-core)
Tested-by: Volodymyr Babchuk <07adff7e050dc3230ac0b7d9c296bbb62f4ecc95@gmail.com> (RCAR H3)
Tested-by: Jerome Forissier <ced78d268b4c9a0a20a59a9feeebd2ad90da03d3@linaro.org> (D02)
Tested by: Victor Chong <victor.chong@linaro.org> (hikey aosp)
Tested-by: Peng Fan <d3c162a96b7fb54e5d94bc77bc2c7cbbce10806f@nxp.com> (imx-mx7dsabresd imx-mx6ulevk imx-mx6ullevk)
Tested-by: Sören Brinkmann <f9793267bd24439886cd4a142f9642a9bcc6364b@xilinx.com> (zynqmp)
Tested-by: Joakim Bech <741f90e2a7f4d9afbad8bd50be20560f4cf38962@linaro.org> (Juno, QEMUv7, QEMUv8, FVP, MTK8173)

pascal-brand-st-dev/optee_os,pascal-brand-st-dev/optee_os,pascal-brand-st-dev/optee_os,pascal-brand-st-dev/optee_os,pascal-brand-st-dev/optee_os