soc: qcom: mdt_loader: Validate that p_filesz < p_memsz

soc: qcom: mdt_loader: Validate that p_filesz < p_memsz

The code validates that segments of p_memsz bytes of a segment will fit
in the provided memory region, but does not validate that p_filesz bytes
will, which means that an incorrectly crafted ELF header might write
beyond the provided memory region.

Fixes: 051fb70fd4ea ("remoteproc: qcom: Driver for the self-authenticating Hexagon v5")
Reviewed-by: Sibi Sankar <sibis@codeaurora.org>
Link: https://lore.kernel.org/r/20210107233119.717173-1-bjorn.andersson@linaro.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>