drm/i915/display/adlp: Fix PSR2_MAN_TRK_CTL_SU_REGION_END_ADDR calculation

As the SU_REGION_START begins at 0, the SU_REGION_END should be number
of lines - 1.

BSpec: 50424
Reviewed-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210914212507.177511-1-jose.souza@intel.com