linuxkpi: Adds more SZ_* macros
SZ_2K and SZ_1G were defined in irdma. They are removed from this
driver.
Reviewed by: manu
Approved by: manu
Differential Revision: https://reviews.freebsd.org/D38150
(cherry picked from commit 04cbeeb59742a9e88d838e18b84004e9bb89ca00)