scsi: lpfc: Update construction of SGL when XPSGL is enabled

scsi: lpfc: Update construction of SGL when XPSGL is enabled

The construction of SGLs is updated to safeguard ASIC boundary requirements
when using XPSGL.

The LSP type SGE is used to notify where a continuing SGL resides.
Typically, this means that the LSP is the last SGE in an SGL because the
current SGL has reached its maximum size and the LSP is used to refer to
the next follow up SGL.  Due to ASIC boundary requirements, there is a need
to ensure a 4 KB boundary is not crossed.  Thus, for a maximum size of 256
byte SGLs or 16 SGEs, this means restricting the LSP to being the 12th SGE
for the very first SGL that is used for pre-registration.  If additional
SGEs are needed, the LSP will be the last SGE position within that follow
up SGL as was previously implemented.

Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Link: https://patch.msgid.link/20260331205928.119833-7-justintee8345@gmail.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>