[FIRMWARE][i.MX8] Change version of DP and HDMI firmware

DP is not functional with the signed_dp_imx8m.bin currently available in BSP from package firmware-imx-8m_8.18: replace it with signed_dp_imx8m.bin from package firmware-imx-8m_8.11, tested and working with: -boe nv133fhm n62 -g156han03 -ivo m133nvf4 The hdmi firmware was also changed to mantain same version, this was tested with: -HTNZIR 14 Inches

The validation report can be seen at https://secogroup.atlassian.net/wiki/spaces/SW/pages/2498002945/C20+Validation+report+-+eDP+and+HDMI+new+firmware