Change in coreboot[master]: soc/mediatek: Save dram info to cbmem

[Yu-Ping Wu (Code Review)]

Attention is currently required from: Hung-Te Lin, Xi Chen, Paul Menzel, Julius Werner, Xixi Chen.
Yu-Ping Wu has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/61334 )

Change subject: soc/mediatek: Save dram info to cbmem
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Patch Set 25: -Code-Review

(1 comment)

File src/soc/mediatek/common/memory.c:

https://review.coreboot.org/c/coreboot/+/61334/comment/49daee2c_42fc3564 
PS22, Line 123: 	p = (void *)((uintptr_t)mc + sizeof(*mc));
> The problem with C99 variable-length arrays is that they make sizeof() illegal. […]

Now I see what the problem is. The error will happen only if x (in Julius' example) points to a global variable, which makes perfect sense since the x->c[2] will definitely access invalid memory. However, I don't know why there won't be errors when x points to a local variable.

In PS18 'p' is pointing to a global variable 'curr_dram_info', which is of course wrong. Now in PS25 we've fixed the problem, so I believe we can access the array by `mc->channel[i]`.