mtd: lpddr_cmds: Add literal suffix

The value of an arithmetic expression
1 << lpddr->qinfo->DevSizeShift is subject to overflow
due to a failure to cast operands to a larger data
type before performing arithmetic

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Denis Arefev <arefev@swemel.ru>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230824130215.10396-1-arefev@swemel.ru