soc: qcom: pmic_glink: remove redundant calculation of svid

gcc with W=1 reports
drivers/soc/qcom/pmic_glink_altmode.c:223:13: error: variable ‘svid’ set but not used [-Werror=unused-but-set-variable]
  223 |         u16 svid;

From reviewing the code, the setting of alt_port->svid does the same calculation.
Both are not needed.  For debuggablity, keep the setting of local svid.

Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230206135831.1794583-1-trix@redhat.com