net: qualcomm: rmnet: Switch page order computation logic

Use the standard page order helper instead of using a custom
definition.

CRs-Fixed: 2512312
Change-Id: I567c3e63915ebcb78b766bc86b069ee01ad3c227
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>