include: configs: j721e_evm.h: Fix the env variable corresponding to QSGMII PHY init

QSGMII PHY initialization should only be done for J721E EVMs and not for
J721E-SK boards. Therefore, fix the environment variables accordingly.

Also, by default remote processors should not be booted in U-Boot but
rather be left to the users to enable this by setting dorprocboot.
Therefore, remove dorprocboot that is being set by default.

Fixes: 5980925e ("include: configs: j721e_evm: Add support to boot ethfw core in j721e")
Reported-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>