remoteproc: qcom: qcom_q6v5_adsp: Fix some return value check

In case of error, the functions devm_kcalloc() and devm_ioremap()
returns NULL pointer not ERR_PTR(). The IS_ERR() test in the return
value check should be replaced with NULL test.

Also removed -EPROBE_DEFER check since devm_kcalloc never return
this error.

Fixes: dc160e44 ("remoteproc: qcom: Introduce Non-PAS ADSP PIL driver")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>