scsi: hisi_sas: Reduce HISI_SAS_SGE_PAGE_CNT in size

driver inclusion
category: bugfix
bugzilla: NA
CVE: NA

Macro HISI_SAS_SGE_PAGE_CNT is defined to SG_CHUNK_SIZE, which is 128.

This means that sizeof(struct hisi_sas_slot_buf_table) is 4192. This is
just over a 4K, which can mean inefficient DMA memory usage (for no PI).

Reduce the size of HISI_SAS_SGE_PAGE_CNT to 124 to fit in a 4K page. With
this change, we experience no performance hit.

Signed-off-by: Wang Chao <wangchao342@hisilicon.com>
Reviewed-by: Zhu Xiongxiong <zhuxiongxiong@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>