fix(rk3399): dram: Fix build with gcc 11

This is a redundant assignment which GCC warns about.

Fixes

plat/rockchip/rk3399/drivers/dram/dram_spec_timing.c:781:11: error: explicitly assigning value of variable of type 'uint32_t' (aka 'unsigned int') to itself [-Werror,-Wself-assign]
                twr_tmp = twr_tmp;
                ~~~~~~~ ^ ~~~~~~~

Signed-off-by: Khem Raj <raj.khem@gmail.com>
[add fix(rk3399): prefix to commit title]
Signed-off-by: Quentin Schulz <quentin.schulz@cherry.de>
Change-Id: Ib12281e0720346ffe68e81a24ea772ddc89d4f83
1 file changed