msm: gsi: Update GSI driver to support 24 event ring channels

GSI 2.5 supports 24 event ring channels as opposed to 22
at previous versions. Update driver to support it.

CRs-Fixed: 2264249
Change-Id: I4b80a5b24c3dad8950ccc2b0a6839fb86879399d
Signed-off-by: Ghanim Fodi <gfodi@codeaurora.org>