kerneldoc: Add myself to the git-mailrc for kerneldoc

Add entry for kerneldoc into the git-mailrc pointing to the U-Boot ML
and myself.
Signed-off-by: NMarek Vasut <marex@denx.de>

doc/git-mailrc

@@ -96,6 +96,7 @@ alias x86            uboot, gruss
 
 # Subsystem aliases
 alias cfi            uboot, stroese
+alias kerneldoc      uboot, marex
 alias fdt            uboot, Jerry Van Baren <vanbaren@cideas.com>
 alias i2c            uboot, hs
 alias mmc            uboot, afleming