thermal: rcar: use mutex lock instead of spin lock
thermal: rcar: use mutex lock instead of spin lock

Current R-Car thermal driver is using spin lock for each
registers read/write, but it is pointless lock.
This lock is required while reading temperature,
but it needs long wait (= 300ms).
So, this patch used mutex lock while reading temperature,
instead of spin lock for each registers.

Signed-off-by: Kuninori Morimoto <a3b51ccb87d18302c1692defcfbf83319d1737eb@renesas.com>
Signed-off-by: Zhang Rui <f2a4cf793007be8f81a774dc7806c1ffea7b4a2c@intel.com>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs