package/cryptodev-linux: ccache compile fix

cryptodev-linux fails to build when BR2_CCACHE=y.

>>> cryptodev-linux 1.7 Building
/usr/bin/make -j5 -C /home/dkehn/buildroot/output/build/cryptodev-linux-1.7 HOSTCC="/home/dkehn/buildroot/output/host/usr/bin/ccache /usr/bin/gcc" HOSTCFLAGS="" ARCH=arm INSTALL_MOD_PATH=/home/dkehn/buildroot/output/target CROSS_COMPILE="/home/dkehn/buildroot/output/host/usr/bin/ccache /home/dkehn/buildroot/output/host/usr/bin/arm-buildroot-linux-gnueabihf-" DEPMOD=/home/dkehn/buildroot/output/host/sbin/depmod LOADADDR="0x82000000" KERNEL_DIR=/home/dkehn/buildroot/output/build/linux-2489c022b2932432606f897741a71b712e6dbe77
make -C /home/dkehn/buildroot/output/build/linux-2489c022b2932432606f897741a71b712e6dbe77 SUBDIRS=`pwd` ARCH=arm CROSS_COMPILE=/home/dkehn/buildroot/output/host/usr/bin/ccache /home/dkehn/buildroot/output/host/usr/bin/arm-buildroot-linux-gnueabihf- modules
make[3]: warning: jobserver unavailable: using -j1.  Add '+' to parent make rule.
make[3]: /home/dkehn/buildroot/output/host/usr/bin/ccachegcc: Command not found

Adding quotes around ${CROSS_COMPILE} KERNEL_MAKE_OPTS assignment in
cryptodev-linux Makefile fixes compile error.

[Thomas: add description and SoB inside the patch.]

Signed-off-by: Doug Kehn <rdkehn@yahoo.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>